**Meet the editor**

Professor Tony G Catto-Smith is Director of the Department of Gastroenterology and Clinical Nutrition at the Royal Children's Hospital, Melbourne. He qualified in medicine from St Bartholomew's Hospital in London, trained in paediatrics in the UK and Australia, then in paediatric gastroenterology at the University of Calgary in Canada. After returning to Melbourne in 1990, he

pioneered the introduction of clinical techniques for the measurement of gastrointestinal motility at RCH. He has continued a strong clinical interest in disorders of colorectal function and published extensively in this area. A major clinical achievement has been the introduction of percutaneous endoscopic gastrostomy placement for children in Australia. Other clinical and research interests include the pathogenesis and treatment of Crohn's and Ulcerative Colitis. He is the author of over 100 journal articles.

### Contents

### **Preface XI**


Elsie E. Gulick and Marie Namey

X Contents

### Chapter 10 **Multimodal Treatment of Constipation: Surgery, Rehabilitation or Both? 139**  Luigi Brusciano, Crescenzo Di Stazio, Paolo Limongelli, Gian Mattia Del Genio, Salvatore Tolone, Saverio Sansone, Francesco Lucido, Ignazio Verde, Antonio D'Alessandro, Roberto Ruggiero, Simona Gili, Assia Topatino, Vincenzo Amoroso, Pina Casalino, Giovanni Docimo and Ludovico Docimo

### Chapter 11 **Core Aspects of Clinical Development and Trials in Chronic Idiopathic Constipation 147**  M. Scott Harris and Oranee T. Daniels

### Preface

Constipation is common in both adults and children. Estimates would suggest a median prevalence of around 12-16% in the general population.1 While regarded as a minor nuisance in some cases, its consequences can be severe, with a substantial impact on quality of life.2 Secondary faecal soiling has a profound psychological effect at all ages.

This book provides specific contributions which clarify the pathogenesis, diagnosis, and therapy of constipation for the general population and also for certain high risk groups.

Surprisingly, consensus definitions of constipation have been hard to achieve, but that achieved by the PACCT group3 for children included having at least 2 of the following features within the last 8 weeks:


Importantly, it may not be recognised, only coming to attention because of abdominal pain, soiling or behavioural disturbances. The chapter by Kathleen McGrath critically examines the impact defaecation disorders have in children and the diagnostic criteria used to identify them.

Defaecation disorders are also much more prevalent in certain groups. The very young and the elderly4, 5 are at particular risk. They also pose a particular difficulty for both children and adults with developmental disabilities6, neurological dysfunction and spinal cord injury.7 Medical and surgical therapy may also lead to constipation through the use of potent analgesics such as opiods. The chapters by Caterina Aurilio and Kelly Sprawls provide insights into the aetiology of opiod-induced constipation and pharmaceutical approaches to avoiding it and its therapy. Occasionally, constipation may be the presenting feature of another condition such as thyroid disease or colorectal malignancy.8 The relationship between colorectal tumors and colonoscopy is addressed in the chapter by Brusciano. The chapters by Luca Galleli

#### X Preface

and Elsie Gulick provide insights into the impact of the broad spectrum of neurological disorders and multiple sclerosis respectively on colorectal dysfunction.

In most situations, constipation occurs in otherwise well individuals. The pathogenesis in these cases is usually proposed to be inadequate dietary fibre, a sedentary lifestyle, or poor toileting techniques. The chapter by Tomoko Fujiwara provides an insightful and unique window into the impact of the all too common habit of skipping breakfast on bowel function.

Diagnosis is usually straightforward, but it often helpful to make reference to diagnostic criteria such as that achieved by the PACCT group. Further diagnostic testing is not usually required, but can be invaluable in specific instances. The chapter on diagnostic tests (Catto-Smith et al.) provides a review of the available testing techniques. While abdominal radiography is often employed, it is rarely adds much. Studies of colorectal motility9, 10 provide an immense amount of information but are either expensive, invasive, or difficult to interpret11. However, they have enabled a better understanding of the motility dysfunction responsible for constipation.12 Sensory dysfunction is clearly important as many patients are unaware of the extent of rectal filling.13 These type of studies have however meant that entities such as slow transit constipation, anorectal incoordination, sphincteric dysfunction and the basis for constipation in irritable bowel syndrome are now much better understood14. The chapter by Brian Dobson provides a novel hypothesis into the pathogenesis of defaecation disorders in irritable bowel syndrome.

In many situations, otherwise uncomplicated constipation will respond to simple interventions such as attention to diet15 and toileting, but in other patients it can be extraordinarily difficult to achieve therapeutic success. Medications generally function through either assisting colorectal contractility or softening the stool.16 Unfortunately, drugs only offer temporary relief if the primary cause is unable to be improved. Recent interest has centred on possibly dysbiotic colonic flora in the hope that probiotics17 may be helpful. There are a variety of traditional and complementary medications that are used widely in the community.18

Behavioural therapies are often very effective in children,19, 20 and biofeedback modalities have attracted a great deal of interest, particularly in adults. 21

Better understanding of the pathophysiology of defaecation disorders has opened the doors to novel treatments. Abnormalities in the excitatory cells primarily responsible controlling gastrointestinal motility have been postulated to have a major role in certain types of constipation such as slow transit22 and even that associated with diabetes.23 The chapter by Christian Breuer provides a good understanding of the Interstitial Cell of Cajal – a central player in gastrointestinal dysmotility and slow transit constipation. Sacral stimulation is certainly effective, but is invasive. A very exciting new area is that of transabdominal electrical stimulation, 24 which appears to offer the unenviable combination of low cost, ease of use, durability of effect to an otherwise treatment-resistant population.25, 26

It goes without saying that the introduction of any new therapy must be accompanied by careful evaluation. The chapter by Scott Harris provides a careful and clear description of the core aspects of clinical development and trials of a range of therapeutic modalities in chronic idiopathic constipation.

> **Anthony G. Catto-Smith**  The Royal Children's Hospital, Melbourne, Australia

#### **References**

X Preface

on bowel function.

defaecation disorders in irritable bowel syndrome.

are used widely in the community.18

otherwise treatment-resistant population.25, 26

and Elsie Gulick provide insights into the impact of the broad spectrum of neurological disorders and multiple sclerosis respectively on colorectal dysfunction.

In most situations, constipation occurs in otherwise well individuals. The pathogenesis in these cases is usually proposed to be inadequate dietary fibre, a sedentary lifestyle, or poor toileting techniques. The chapter by Tomoko Fujiwara provides an insightful and unique window into the impact of the all too common habit of skipping breakfast

Diagnosis is usually straightforward, but it often helpful to make reference to diagnostic criteria such as that achieved by the PACCT group. Further diagnostic testing is not usually required, but can be invaluable in specific instances. The chapter on diagnostic tests (Catto-Smith et al.) provides a review of the available testing techniques. While abdominal radiography is often employed, it is rarely adds much. Studies of colorectal motility9, 10 provide an immense amount of information but are either expensive, invasive, or difficult to interpret11. However, they have enabled a better understanding of the motility dysfunction responsible for constipation.12 Sensory dysfunction is clearly important as many patients are unaware of the extent of rectal filling.13 These type of studies have however meant that entities such as slow transit constipation, anorectal incoordination, sphincteric dysfunction and the basis for constipation in irritable bowel syndrome are now much better understood14. The chapter by Brian Dobson provides a novel hypothesis into the pathogenesis of

In many situations, otherwise uncomplicated constipation will respond to simple interventions such as attention to diet15 and toileting, but in other patients it can be extraordinarily difficult to achieve therapeutic success. Medications generally function through either assisting colorectal contractility or softening the stool.16 Unfortunately, drugs only offer temporary relief if the primary cause is unable to be improved. Recent interest has centred on possibly dysbiotic colonic flora in the hope that probiotics17 may be helpful. There are a variety of traditional and complementary medications that

Behavioural therapies are often very effective in children,19, 20 and biofeedback

Better understanding of the pathophysiology of defaecation disorders has opened the doors to novel treatments. Abnormalities in the excitatory cells primarily responsible controlling gastrointestinal motility have been postulated to have a major role in certain types of constipation such as slow transit22 and even that associated with diabetes.23 The chapter by Christian Breuer provides a good understanding of the Interstitial Cell of Cajal – a central player in gastrointestinal dysmotility and slow transit constipation. Sacral stimulation is certainly effective, but is invasive. A very exciting new area is that of transabdominal electrical stimulation, 24 which appears to offer the unenviable combination of low cost, ease of use, durability of effect to an

modalities have attracted a great deal of interest, particularly in adults. 21


XII Preface

2011;25:103-18.

2011;33:895-901.

2011;60:209-18.

2010;16:69-75.

2005;182:242-6.

2009;21 Suppl 2:55-61.

International 2007;23:1179-82.

Hepatology 2008;23:505-7.

Gastroenterology 2011;25:181-91.

Pediatric Surgery 2009;44:2388-92.

Journal of Pediatric Surgery 2009;44:408-12.

[12] King SK, Catto-Smith AG, Stanton MP, Sutcliffe JR, Simpson D, Cook I, Dinning

[13] Scott SM, van den Berg MM, Benninga MA. Rectal sensorimotor dysfunction in

[14] Dinning PG, Di Lorenzo C. Colonic dysmotility in constipation. Best Practice &

[15] Suares NC, Ford AC. Systematic review: the effects of fibre in the management of

[16] Ford AC, Suares NC. Effect of laxatives and pharmacological therapies in chronic

[17] Chmielewska A, Szajewska H. Systematic review of randomised controlled trials:

[18] Cheng CW, Bian ZX, Wu TX. Systematic review of Chinese herbal medicine for functional constipation. World Journal of Gastroenterology 2009;15:4886-95. [19] Catto-Smith AG. 5. Constipation and toileting issues in children. Med J Aust

[20] Whitehead WE, di Lorenzo C, Leroi AM, Porrett T, Rao SS. Conservative and

[21] Koh CE, Young CJ, Young JM, Solomon MJ. Systematic review of randomized

[22] Sutcliffe J, King SK, Clarke MC, Farmer P, Hutson JM, Southwell BR. Reduced

[23] Southwell BR, Southwell BR. Loss of interstitial cells of Cajal may be central to

[24] van Wunnik BP, Baeten CG, Southwell BR. Neuromodulation for constipation:

[25] Ismail KA, Chase J, Gibb S, Clarke M, Catto-Smith AG, Robertson VJ, Hutson JM,

[26] Clarke MC, Chase JW, Gibb S, Robertson VJ, Catto-Smith A, Hutson JM,

dysfunction. British Journal of Surgery 2008;95:1079-87.

American Journal of Gastroenterology 2008;103:2083-91.

Research in Clinical Gastroenterology 2011;25:89-101.

P, Hutson JM, Southwell BR. 24-Hour colonic manometry in pediatric slow transit constipation shows significant reductions in antegrade propagation.

constipation. Best Practice & Research in Clinical Gastroenterology

chronic idiopathic constipation. Alimentary Pharmacology & Therapeutics

idiopathic constipation: systematic review and meta-analysis. Gut

probiotics for functional constipation. World Journal of Gastroenterology

behavioural management of constipation. Neurogastroenterology & Motility

controlled trials of the effectiveness of biofeedback for pelvic floor

distribution of pacemaking cells in dilated colon. Pediatric Surgery

poor intestinal motility in diabetes mellitus. Journal of Gastroenterology &

sacral and transcutaneous stimulation. Best Practice & Research in Clinical

Southwell BR. Daily transabdominal electrical stimulation at home increased defecation in children with slow-transit constipation: a pilot study. Journal of

Southwell BR. Decreased colonic transit time after transcutaneous interferential electrical stimulation in children with slow transit constipation.

### **Diagnostic Approach to Constipation in Children**

Kathleen H. McGrath1 and Patrina Caldwell2

*1The Royal Children's Hospital, Melbourne 2University of Sydney, The Children's Hospital at Westmead, Sydney Australia* 

### **1. Introduction**

Constipation is a common paediatric problem. It is relevant to the practice of both general paediatricians and paediatric gastroenterologists and accounts for 3% and 25% of outpatient visits respectively (Levine, 1975; Taitz et al., 1986). International prevalence rates range from 0.7% to 29.6% which is similar for males and females (van den Berg et al., 2006). The broad range of reported prevalence is related to differing criteria for defining constipation but may also reflect genuine differences between ethnic populations and socioeconomic influences.

The diagnosis of constipation is historically a subjective and symptom-based approach. It relies on good clinical history taking and physical examination, in particular to exclude an underlying organic aetiology. In order to objectify the classification of this entity and allow for comparison of data between studies (e.g. prevalence rates, treatment outcomes), a number of diagnostic classifications have been proposed. This chapter will discuss the origin of these various classifications, their application and role within paediatric clinical practice and research. It will also provide a suggested clinical approach to the diagnosis of constipation in children, including the problems that may be encountered.

### **2. Importance of the appropriate diagnosis of constipation in children**

Symptoms of childhood constipation may vary from mild and short-lived to severe and chronic. It can affect children in all age groups from infants to adolescents and can extend into adulthood.

Constipation is associated with a wide range of consequences for the individual child. These include physical pain and discomfort, psychological distress (primarily related to faecal incontinence) and an increased risk of urinary dysfunction. It can also impact on quality of life, family dynamics and socialisation through missed days of school and work (Belsey et al., 2010). In some children, a delayed or missed diagnosis can result in progression towards a significant chronic health problem with physical, psychological and social implications.

### **2.1 Impact on the child: Physical discomfort associated with constipation**

Constipation is associated with varying degrees of physical discomfort for children. The onset of constipation is often related to experience(s) of painful defaecation. This may be caused by the presence of an anal fissure, perianal infection or perianal inflammation due to cow's milk protein intolerance or other underlying medical conditions. Once children experience discomfort, they commonly associate the process of defaecation with pain and actively attempt to avoid it. This may manifest as toilet refusal or stool withholding behaviours where there is voluntary contraction of the external anal sphincter with the urge to defaecate.

Repetitive withholding behaviours result in further constipation as the brain begins to ignore the signals that would usually alert the child to the need to defaecate (Weaver & Dobson, 2007). This results in stools that are hard, large and difficult to pass which can lead to further experiences of pain and the development of perianal tears, perpetuating the cycle of painful defaecation, stool withholding and worsening constipation.

Constipation is one of the most frequent causes for abdominal pain in children presenting to their medical practitioner or the emergency department. One study found that acute or chronic constipation accounted for 48% of children with acute abdominal pain presenting to a large academic paediatric primary care population (Loening-Baucke & Swidsinski, 2007).

Ongoing chronic constipation results in stool impaction, distension of the rectum and sigmoid colon and rectal insensitivity. Stool impaction can cause abdominal pain which may vary from mild to severe in nature. Children with constipation may also experience systemic symptoms including loss of appetite, nausea, vomiting and weight loss.

### **2.2 Impact on the child: Chronic constipation and quality of life**

Constipation can affect a child's physical and mental wellbeing and impact on their overall quality of life. Section 2.1 described the common physical manifestations of constipation including pain.

Studies have further assessed the impact of chronic constipation on a child's emotional status. One Australian study assessed a cohort of children with slow transit constipation (confirmed on radioisotope study) and compared them with a group of healthy children with normal bowel patterns. The study found that children with constipation reported a significantly lower quality of life (assessed by questionnaires addressing domains of physical, emotional, social and school functioning) compared with the non-constipated children. In addition, the parents of these children reported a significantly lower quality of life for their child than the child's self-reporting using the same scoring system (Clarke et al, 2008). Constipation not only affects the individual child's quality of life, but may impact on their relationship with parents and / or siblings and the family dynamics as a whole.

Another study compared children with constipation to groups of children with inflammatory bowel disease, gastro-oesophageal reflux disease or normal health. They found that children with constipation reported a significantly lower quality of life (assessed by self and parental reporting) compared with both healthy children and children with inflammatory bowel disease or gastro-oesophageal reflux disease (Youssef et al., 2005). This was a pertinent finding considering that inflammatory bowel disease is traditionally accepted by physicians and the general population as being a more serious condition than constipation.

A recent systematic review by Belsey and colleagues demonstrated that impaired quality of life is a consistent finding in children and adults with chronic constipation. They found that the quality of life in children with chronic constipation was comparable to those of children

cow's milk protein intolerance or other underlying medical conditions. Once children experience discomfort, they commonly associate the process of defaecation with pain and actively attempt to avoid it. This may manifest as toilet refusal or stool withholding behaviours where there is voluntary contraction of the external anal sphincter with the urge

Repetitive withholding behaviours result in further constipation as the brain begins to ignore the signals that would usually alert the child to the need to defaecate (Weaver & Dobson, 2007). This results in stools that are hard, large and difficult to pass which can lead to further experiences of pain and the development of perianal tears, perpetuating the cycle

Constipation is one of the most frequent causes for abdominal pain in children presenting to their medical practitioner or the emergency department. One study found that acute or chronic constipation accounted for 48% of children with acute abdominal pain presenting to a large academic paediatric primary care population (Loening-Baucke & Swidsinski, 2007). Ongoing chronic constipation results in stool impaction, distension of the rectum and sigmoid colon and rectal insensitivity. Stool impaction can cause abdominal pain which may vary from mild to severe in nature. Children with constipation may also experience systemic

Constipation can affect a child's physical and mental wellbeing and impact on their overall quality of life. Section 2.1 described the common physical manifestations of constipation

Studies have further assessed the impact of chronic constipation on a child's emotional status. One Australian study assessed a cohort of children with slow transit constipation (confirmed on radioisotope study) and compared them with a group of healthy children with normal bowel patterns. The study found that children with constipation reported a significantly lower quality of life (assessed by questionnaires addressing domains of physical, emotional, social and school functioning) compared with the non-constipated children. In addition, the parents of these children reported a significantly lower quality of life for their child than the child's self-reporting using the same scoring system (Clarke et al, 2008). Constipation not only affects the individual child's quality of life, but may impact on

their relationship with parents and / or siblings and the family dynamics as a whole.

general population as being a more serious condition than constipation.

Another study compared children with constipation to groups of children with inflammatory bowel disease, gastro-oesophageal reflux disease or normal health. They found that children with constipation reported a significantly lower quality of life (assessed by self and parental reporting) compared with both healthy children and children with inflammatory bowel disease or gastro-oesophageal reflux disease (Youssef et al., 2005). This was a pertinent finding considering that inflammatory bowel disease is traditionally accepted by physicians and the

A recent systematic review by Belsey and colleagues demonstrated that impaired quality of life is a consistent finding in children and adults with chronic constipation. They found that the quality of life in children with chronic constipation was comparable to those of children

of painful defaecation, stool withholding and worsening constipation.

symptoms including loss of appetite, nausea, vomiting and weight loss.

**2.2 Impact on the child: Chronic constipation and quality of life** 

to defaecate.

including pain.

with other chronic conditions traditionally regarded as being more serious, including cardiac and rheumatologic diseases (Belsey et al., 2010).

The diagnosis of chronic constipation in children should be taken seriously as its impact on quality of life may be far greater than initially anticipated. It should be considered a public health issue for primary physicians, paediatricians and paediatric gastroenterologists. Further studies are needed to specifically assess the impact of this condition on quality of life when it lasts from childhood into adulthood.

### **2.3 Impact on the child: Faecal incontinence and psychological distress**

Faecal incontinence refers to the passage of stools in an inappropriate place (Benninga et al., 2005). It occurs in 1-3% of children and can affect up to 8% of adults (Catto-Smith, 2005). Faecal incontinence is a frequent accompanying symptom of childhood constipation. Studies show that it is present in up to 84% of children with constipation (Vooskijl et al., 2004). In around 80% of cases of faecal incontinence, it is involuntary and occurs in the setting of chronic constipation (constipation-associated faecal incontinence) (Joinson et al., 2006). Less commonly faecal incontinence can be voluntary (non-retentive faecal incontinence) and may be related to emotional disturbance with no evidence of constipation being present.

Functional constipation and stool withholding behaviours lead to impaction of faeces in the rectum, distension of the rectum and sigmoid colon and rectal insensitivity which may result in faecal incontinence. Due to rectal insensitivity, children may not be aware of this happening. Risk factors for faecal incontinence are listed in Table 1.

Faecal incontinence is associated with behavioural and emotional problems in children. A recent population study of over 8000 children found significantly higher rates of behavioural and emotional problems in children with faecal incontinence compared to those without. In addition they noted that these problems were significantly greater in children who soiled frequently compared with those who soiled only occasionally (less than once per week) (Joinson et al., 2006).


Children may be embarrassed by their faecal incontinence, associated body odour and differences from their peers. This is particularly the case for school-aged children who may

Table 1. Risk factors for faecal incontinence (modified from Ho & Caldwell, 2008).

experience teasing or bullying and social isolation. Constant focus on the child's bowel habits from the parents may distress the child and cause conflict within the home between family members. Parents may wrongly 'blame' the child for being 'lazy' and punish them unnecessarily, causing further emotional distress. The child's degree of distress and low selfesteem may affect their behaviour and cause them to become withdrawn or alternatively 'act up'. There may be considerable negative implications on their learning and performance at school. Further consequences may include missed days of school and work for parents, leading to societal costs on a wider scale.

### **2.4 Impact on the child: Urinary dysfunction**

Epidemiological studies have identified an association between constipation and certain urological conditions. These include urinary incontinence, vesicoureteric reflux and urinary tract infections (McGrath & Caldwell, 2008; Loening-Baucke, 1997; O'Regan et al., 1985, 1986). Loening-Baucke assessed 234 children with chronic constipation and found that 29% had daytime urinary incontinence and 11% had a urinary tract infection. A more recent Australian study found a prevalence of constipation of 36.1% in a population of children with nocturnal enuresis (McGrath & Caldwell, 2008), which is higher than reported international prevalence rates of 0.7% to 29.6% in the normal population.

With successful treatment of constipation, many of these urinary symptoms will resolve. In one study, successful treatment of constipation after 12 months resulted in resolution of daytime urinary incontinence in 89% and urinary tract infection in all patients with normal urinary tract anatomy (Loening-Baucke, 1997).

### **2.5 Impact on the child: Outcome of late or missed diagnosis**

A timely diagnosis of constipation can help to prevent or minimise many of the complications outlined above. If constipation is identified early, management can be initiated in the form of education, toileting programs, dietary modification, behavioural therapy and laxatives. Successful intervention to 'keep the rectum empty' will avoid progression to stool impaction, rectal distension and insensitivity and the onset of faecal incontinence. In addition, the early identification and management of constipation has been shown to result in better treatment response and outcomes (Van Ginkel et al., 2003). This was particularly the case when children were referred for management of constipation under the age of 2 years (Loening-Baucke, 1993).

Missed or delayed diagnosis of constipation can increase the risk of both physical and psychological complications, making the problem more difficult to manage later on. Where urinary dysfunction exists in the context of chronic constipation, a missed diagnosis of constipation may result in treatment failure. An accurate diagnosis of constipation is paramount for provision of optimal patient care and quality of life.

### **3. The use of diagnostic criteria in childhood constipation**

### **3.1 Definitions and Historical overview**

The term 'constipation' derives from the Latin 'constipare' meaning to crowd together. The accepted understanding of constipation describes a constellation of different symptoms

experience teasing or bullying and social isolation. Constant focus on the child's bowel habits from the parents may distress the child and cause conflict within the home between family members. Parents may wrongly 'blame' the child for being 'lazy' and punish them unnecessarily, causing further emotional distress. The child's degree of distress and low selfesteem may affect their behaviour and cause them to become withdrawn or alternatively 'act up'. There may be considerable negative implications on their learning and performance at school. Further consequences may include missed days of school and work for parents,

Epidemiological studies have identified an association between constipation and certain urological conditions. These include urinary incontinence, vesicoureteric reflux and urinary tract infections (McGrath & Caldwell, 2008; Loening-Baucke, 1997; O'Regan et al., 1985, 1986). Loening-Baucke assessed 234 children with chronic constipation and found that 29% had daytime urinary incontinence and 11% had a urinary tract infection. A more recent Australian study found a prevalence of constipation of 36.1% in a population of children with nocturnal enuresis (McGrath & Caldwell, 2008), which is higher than reported

With successful treatment of constipation, many of these urinary symptoms will resolve. In one study, successful treatment of constipation after 12 months resulted in resolution of daytime urinary incontinence in 89% and urinary tract infection in all patients with normal

A timely diagnosis of constipation can help to prevent or minimise many of the complications outlined above. If constipation is identified early, management can be initiated in the form of education, toileting programs, dietary modification, behavioural therapy and laxatives. Successful intervention to 'keep the rectum empty' will avoid progression to stool impaction, rectal distension and insensitivity and the onset of faecal incontinence. In addition, the early identification and management of constipation has been shown to result in better treatment response and outcomes (Van Ginkel et al., 2003). This was particularly the case when children were referred for management of constipation

Missed or delayed diagnosis of constipation can increase the risk of both physical and psychological complications, making the problem more difficult to manage later on. Where urinary dysfunction exists in the context of chronic constipation, a missed diagnosis of constipation may result in treatment failure. An accurate diagnosis of constipation is

The term 'constipation' derives from the Latin 'constipare' meaning to crowd together. The accepted understanding of constipation describes a constellation of different symptoms

international prevalence rates of 0.7% to 29.6% in the normal population.

**2.5 Impact on the child: Outcome of late or missed diagnosis** 

paramount for provision of optimal patient care and quality of life.

**3. The use of diagnostic criteria in childhood constipation** 

leading to societal costs on a wider scale.

**2.4 Impact on the child: Urinary dysfunction** 

urinary tract anatomy (Loening-Baucke, 1997).

under the age of 2 years (Loening-Baucke, 1993).

**3.1 Definitions and Historical overview** 

related to difficult passage of stool. These may include infrequent passage of stool, firm stool consistency, straining and painful defaecation, retentive posturing and faecal incontinence. The subjective nature of these symptoms has historically made defining and diagnosing constipation a challenge and there is no consensus on the definition for 'constipation'. This has limited the ability of researchers to accurately compare different clinical studies in this field and accounts in part for the wide range of reported international prevalence.

In an attempt to standardise the definition of constipation and the related disorders of gastrointestinal motility, diagnostic criteria were created. Generally, these separate functional constipation from that secondary to medical illnesses and medications. They are outlined below and summarised in Table 2.

Early attempts to formalise a definition of constipation included the Iowa classic criteria. This classification was used by some groups in clinical research for the last two decades but its application in clinical practice was sporadic and the mainstream diagnosis of constipation remained largely subjective.

In 1989, a group of investigators met in Rome to form a consensus opinion to assist in the diagnosis of functional gastrointestinal disorders (FGID). Initially the group focussed on the adult population. In 1997, at a consensus conference, the Rome I Criteria were discussed with relation to childhood, forming the Paediatric Rome II Criteria (published in 1999). Also in 1997, the Bristol Stool Chart was published as an aid for classification of stool by appearance and consistency (Lewis & Heaton, 1997) (see Figure 1). Interpretation of these illustrations was extrapolated to help assist in the diagnosis of constipation (Table 2).

Fig. 1. Bristol stool chart (Lewis and Heaton, 1997).

### **Bristol stool** chart (see Fig. 1.)

Constipation indicated by Types 1 and 2

(Types 4 > 3 being the 'ideal stools' and Types 5 to 7 tending towards diarrhoea) (Lewis & Heaton, 1997)

### **Classic Iowa criteria**

Paediatric constipation = at least 2 of the following criteria:


Solitary encopresis = in a child older than 4 years of age:


No passage of very large amounts of stool

(Loening-Baucke, 1990, as cited in Benninga et al., 2004)

### **Rome II criteria**

Functional constipation: In infants and preschool children (from 1 month to 6 years), at least 2 weeks of


Functional faecal retention: From infancy to 16 years old, a history of at least 12 weeks of


Functional non-retentive faecal soiling: Once a week or more for the preceding 12 weeks, in a child over age 4 years, a history of defaecation


In the absence of signs of faecal retention.

(Rasquin-Weber et al., 1999)

### **Working group report of the first world congress of Paediatric Gastroenterology, Hepatology, and Nutrition**

Constipation is a symptom defined by the occurrence of any of the following, independent of stool frequency:


 Passage of large stools that may clog the toilet Or stool frequency less than 3 per week, unless the child is breast fed. (Hyams et al., 2002)

### **PACCT criteria**

6 Constipation – Causes, Diagnosis and Treatment

 Periodic passage of very large amounts of stool once every 7 to 30 days (the criterion of a large amount of stool is satisfied if it is estimated to be twice the standard amount of stool, shown in a clay model, or is stools are so large that they clog the

Functional constipation: In infants and preschool children (from 1 month to 6 years), at

Functional faecal retention: From infancy to 16 years old, a history of at least 12 weeks of

 Retentive posturing, avoiding defecation by purposefully contracting the pelvic floor. As pelvic floor muscles fatigue, the child uses the gluteal muscles, squeezing

Functional non-retentive faecal soiling: Once a week or more for the preceding 12 weeks,

**Working group report of the first world congress of Paediatric Gastroenterology,** 

Constipation is a symptom defined by the occurrence of any of the following,

Passage of hard, scybalous, pebble-like or cylindrical cracked stools

(Types 4 > 3 being the 'ideal stools' and Types 5 to 7 tending towards diarrhoea)

**Bristol stool** chart (see Fig. 1.)

(Lewis & Heaton, 1997)

**Classic Iowa criteria** 

toilet).

**Rome II criteria** 

least 2 weeks of

Constipation indicated by Types 1 and 2

 Defecation frequency <3 times per week Two or more encopresis episodes per week

Paediatric constipation = at least 2 of the following criteria:

Solitary encopresis = in a child older than 4 years of age:

(Loening-Baucke, 1990, as cited in Benninga et al., 2004)

Scybalous, pebble-like, hard stools in a majority of stools, or

No evidence of structural, endocrine, or metabolic disease

Passage of large-diameter stools at intervals <2 times/week, and

 Two or more encopresis episodes per week Defecation frequency ≥3 times per week No passage of very large amounts of stool

Firm stools 2 or fewer times/week, and

in a child over age 4 years, a history of defaecation

In the absence of signs of faecal retention.

 In places and at times inappropriate to the social context In the absence of structural or inflammatory disease, and

the buttocks together.

(Rasquin-Weber et al., 1999)

**Hepatology, and Nutrition** 

independent of stool frequency:

Straining or painful defecation

Chronic constipation: Occurrence of 2 or more of the following characteristics during the preceding 8 weeks:


Faecal incontinence: Passage of stools in an inappropriate place

	- Constipation-associated faecal incontinence: functional faecal incontinence associated with the presence of constipation
	- Non-retentive (non-constipation-associated) faecal incontinence: passage of stools in an inappropriate place, occurring in children with a mental age of 4 years and older, with no evidence of constipation based on history and/or examination

(Benninga et al., 2005)

### **Rome III criteria**

Functional constipation: Must include 1 month of at least 2 of the following in infants up to 4 years of age:


(Hyman et al., 2006)

Functional constipation: Must include 2 or more of the following in a child with a developmental age of at least 4 years with insufficient criteria for diagnosis of irritable bowel syndrome:


Criteria must be fulfilled at least once per week for at least 2 months before diagnosis (Rasquin et al., 2006)

Non-retentive faecal incontinence: Must include all of the following in a child with a developmental age of at least 4 years:


Table 2. Different classification for childhood constipation.

Some paediatric gastroenterologists and paediatricians found the symptom based Paediatric Rome II Criteria to be too restrictive (see section 3.2). In light of this, a group of experts (paediatric gastroenterologists and paediatricians) gathered in Paris in 2004 to redefine working definitions in gastrointestinal motility (The Paris Consensus on Childhood Constipation Terminology (PACCT) Group). The definition of functional constipation described by PACCT was published in its own right in 2005.

PACCT also recommended discontinuation of the terms 'encopresis' and 'soiling' and replacement by the term 'faecal incontinence'. Soiling was a term that had often been used mutually with encopresis but was felt by the PACCT group to be too broad with possible negative connotations of dirtiness and blame in some cultures. Likewise, the term encopresis was used widely with variable degrees of interpretation and understanding. Some clinicians used this term to refer to intentional passage of stool in a socially inappropriate place (often associated with a psychological disorder). It was thought that discontinuing these two terms in favour of the more strictly defined 'faecal incontinence' would lead to more agreement in understanding and a greater capacity to properly compare different clinical studies. Faecal incontinence was defined as passage of stools in an inappropriate place. For the purposes of this chapter, we will use the term 'faecal incontinence' in place of 'encopresis' or 'soiling', including where studies were published prior to PACCT in 2005.

PACCT was further used to assist in the development of the Rome III Criteria (published in 2006). The Rome III Criteria addressed previously perceived problems such as age restriction (infants versus children / adolescents) and retentive posturing as a component symptom which will be discussed in more detail in Section 3.2.

### **3.2 Comparison and contrast of diagnostic classifications for constipation**

There continues to be varying opinions on the benefits and limitations of the different diagnostic classifications for constipation. The intention behind their derivation was to 'objectify' the ability to diagnose constipation, to allow for comparison between clinical research studies and to aid in the identification of this common paediatric problem in clinical practice. Table 3 summarises the various differences and similarities between the criteria of the classification systems. Below, we have provided a more detailed description of the comparison and contrast between these classifications.

In order to be useful, a diagnostic classification must be shown to be reliable, valid and applicable for a range of relevant population groups. There were a few early attempts to validate the Rome II criteria for functional gastrointestinal disorders. Some studies found the Rome II criteria were helpful for diagnosing functional gastrointestinal disorders in

Non-retentive faecal incontinence: Must include all of the following in a child with a

Some paediatric gastroenterologists and paediatricians found the symptom based Paediatric Rome II Criteria to be too restrictive (see section 3.2). In light of this, a group of experts (paediatric gastroenterologists and paediatricians) gathered in Paris in 2004 to redefine working definitions in gastrointestinal motility (The Paris Consensus on Childhood Constipation Terminology (PACCT) Group). The definition of functional constipation

PACCT also recommended discontinuation of the terms 'encopresis' and 'soiling' and replacement by the term 'faecal incontinence'. Soiling was a term that had often been used mutually with encopresis but was felt by the PACCT group to be too broad with possible negative connotations of dirtiness and blame in some cultures. Likewise, the term encopresis was used widely with variable degrees of interpretation and understanding. Some clinicians used this term to refer to intentional passage of stool in a socially inappropriate place (often associated with a psychological disorder). It was thought that discontinuing these two terms in favour of the more strictly defined 'faecal incontinence' would lead to more agreement in understanding and a greater capacity to properly compare different clinical studies. Faecal incontinence was defined as passage of stools in an inappropriate place. For the purposes of this chapter, we will use the term 'faecal incontinence' in place of 'encopresis' or 'soiling',

PACCT was further used to assist in the development of the Rome III Criteria (published in 2006). The Rome III Criteria addressed previously perceived problems such as age restriction (infants versus children / adolescents) and retentive posturing as a component

There continues to be varying opinions on the benefits and limitations of the different diagnostic classifications for constipation. The intention behind their derivation was to 'objectify' the ability to diagnose constipation, to allow for comparison between clinical research studies and to aid in the identification of this common paediatric problem in clinical practice. Table 3 summarises the various differences and similarities between the criteria of the classification systems. Below, we have provided a more detailed description of

In order to be useful, a diagnostic classification must be shown to be reliable, valid and applicable for a range of relevant population groups. There were a few early attempts to validate the Rome II criteria for functional gastrointestinal disorders. Some studies found the Rome II criteria were helpful for diagnosing functional gastrointestinal disorders in

**3.2 Comparison and contrast of diagnostic classifications for constipation** 

 Defecation into places inappropriate to the social context at least once per month No evidence of an inflammatory, anatomic, metabolic or neoplastic process that

developmental age of at least 4 years:

 explains the subject's symptoms No evidence of faecal retention.

Table 2. Different classification for childhood constipation.

described by PACCT was published in its own right in 2005.

including where studies were published prior to PACCT in 2005.

symptom which will be discussed in more detail in Section 3.2.

the comparison and contrast between these classifications.

childhood however these studies were conducted in a tertiary setting, and may not be generalisable (Miele et al., 2004; Caplan et al., 2005).


Table 3. Comparison of criteria of different classifications for childhood constipation

Since their origin, the Rome II criteria have been widely criticised for being too restrictive. Studies have compared the diagnosis of constipation by the Rome II criteria with other classification systems. One study compared the Rome II criteria with the classic Iowa criteria in identification of constipation in 198 otherwise healthy children referred to a tertiary centre for defaecation disorders. They found the prevalence of constipation was 69% by the Rome II criteria and 74% by the classic Iowa criteria (Voskijl et al., 2004). These results suggest that some children may be missed by the Rome II criteria. A similar study from Turkey assessing children referred to general paediatric or paediatric gastroenterology units for constipation found a prevalence of 72.5% by the Iowa criteria compared with 63.7% by the Rome II criteria (Aydogdu et al., 2009).

One of the main aspects of the Rome II criteria which has restricted its capacity for identification of constipation in children is its exclusion of faecal incontinence as a criterion. Faecal incontinence is common and may affect up to 84% of constipated children (Vooskijl et al., 2004). Exclusion of this relatively frequent symptom may lead to under diagnosis. This was illustrated in the study by Voskijl et al comparing the Rome II diagnostic criteria with the classic Iowa criteria. 16% of children diagnosed with constipation by the classic Iowa criteria did not fulfil the Rome II criteria. These children had low defaecation frequency in combination with encopresis and / or faecal retention (Voskijl et al., 2004). Faecal incontinence is not part of the Rome II criteria. This was considered in creation of the PACCT and Rome III criteria in 2004 and 2006 respectively, with inclusion of 'faecal incontinence more than once per week' as a component criterion for these classifications.

Another group assessed the prevalence of functional defaecation disorders (including constipation) according to PACCT versus Rome II criteria and attempted to compare their clinical validity (Boccia et al., 2007). They found that 53 of 126 (42.1%) of children defined as constipated by PACCT criteria were not recognised by the Rome II criteria, and one child was diagnosed as constipated by Rome II criteria and not PACCT. Many of the children missed by Rome II criteria were excluded purely on the basis of its age restrictions (i.e. not between 1 month and 6 years). This criterion excludes all children greater than 6 years old with constipation regardless of whether they fulfil the other symptom criteria. This stringency is likely to fail to diagnose constipation in older children and supports previous opinion that the Rome II criteria are too restrictive.

In 2005, the PACCT criteria attempted to provide an expert consensus on working definitions in childhood defaecation disorders. The two most pertinent changes were the unification of 'Rome II functional constipation' and 'functional faecal retention' to 'chronic constipation' and the replacement of the terms 'soiling' and 'encopresis' with 'faecal incontinence'. Stool withholding behaviours or retentive posturing was also included as a new criterion although some physicians feel these behaviours may be difficult for parents to recognise in their child.

The Rome III criteria are really an extension of the PACCT criteria but with different duration requirements for different age groups (symptoms for at least 1 month in infants/ children under 4 years old and for at least 2 months in children older than 4 years). With regard to symptom duration, the reduced requirement from symptoms of 3 months duration to 1 month (in infants / toddlers) and to 2 months in children greater than 4 years old/ adolescents was one of the pertinent changes from Rome II to Rome III. This was particularly important in light of recognition that earlier identification of constipation and treatment intervention is associated with a better treatment response and outcome.

There are some studies comparing the Rome III and PACCT classifications. Many of these studies were conducted in populations of children referred to tertiary centres and so their results may not be generalisable to children in the community. One study from Sri Lanka which may be more applicable to children in the community compared Rome III and PACCT criteria for diagnosing constipation among school children aged 10-16 years old. They performed a cross-sectional survey in 5 classes randomly selected from a semi-urban school using a validated, self administered questionnaire with guidance from research assistants. The prevalence of constipation was 10.7% by both the Rome III and PACCT criteria suggesting a level of agreement between the classifications (Rajindrajith et al., 2009).

One criticism of PACCT has been the exclusion of 'scybalous, pebble-like stools' as a criterion for constipation. Some groups have shown that a high percentage of constipated children report this symptom and advocate for its inclusion in future diagnostic criteria (Boccia et al., 2007; Maffei & Morais, 2005). The Rome III classification does not directly refer to this condition but does have 'history of painful or hard bowel movements' as one of its criteria which may incorporate this criterion. Similarly, straining that is not accompanied by pain has been suggested for inclusion in future classifications in light of its relatively frequent reporting in constipated children. One recent study in Sri Lanka identified straining in 75% of children with constipation (as defined by both the PACCT and Rome III criteria) (Rajindrajith et al., 2009).

Another criticism of PACCT has been that 'large faecal mass in the rectum' (a criteria only ascertained by physical examination or an abdominal radiograph) may be difficult to assess in large community surveys (without the involvement of an assessing clinician) (Maffei and Morais, 2005). There is a strong need to address the applicability and validity of the Rome III diagnostic classification for constipation in both primary care and community settings.

Some of the above concerns were addressed by the 'Boston working group' in their definition of constipation in children (Hyams et al, 2002) (see Table 2). This is another

between 1 month and 6 years). This criterion excludes all children greater than 6 years old with constipation regardless of whether they fulfil the other symptom criteria. This stringency is likely to fail to diagnose constipation in older children and supports previous

In 2005, the PACCT criteria attempted to provide an expert consensus on working definitions in childhood defaecation disorders. The two most pertinent changes were the unification of 'Rome II functional constipation' and 'functional faecal retention' to 'chronic constipation' and the replacement of the terms 'soiling' and 'encopresis' with 'faecal incontinence'. Stool withholding behaviours or retentive posturing was also included as a new criterion although some physicians feel these behaviours may be difficult for parents to recognise in their child. The Rome III criteria are really an extension of the PACCT criteria but with different duration requirements for different age groups (symptoms for at least 1 month in infants/ children under 4 years old and for at least 2 months in children older than 4 years). With regard to symptom duration, the reduced requirement from symptoms of 3 months duration to 1 month (in infants / toddlers) and to 2 months in children greater than 4 years old/ adolescents was one of the pertinent changes from Rome II to Rome III. This was particularly important in light of recognition that earlier identification of constipation and

treatment intervention is associated with a better treatment response and outcome.

There are some studies comparing the Rome III and PACCT classifications. Many of these studies were conducted in populations of children referred to tertiary centres and so their results may not be generalisable to children in the community. One study from Sri Lanka which may be more applicable to children in the community compared Rome III and PACCT criteria for diagnosing constipation among school children aged 10-16 years old. They performed a cross-sectional survey in 5 classes randomly selected from a semi-urban school using a validated, self administered questionnaire with guidance from research assistants. The prevalence of constipation was 10.7% by both the Rome III and PACCT criteria suggesting a level of agreement between the classifications (Rajindrajith et al., 2009). One criticism of PACCT has been the exclusion of 'scybalous, pebble-like stools' as a criterion for constipation. Some groups have shown that a high percentage of constipated children report this symptom and advocate for its inclusion in future diagnostic criteria (Boccia et al., 2007; Maffei & Morais, 2005). The Rome III classification does not directly refer to this condition but does have 'history of painful or hard bowel movements' as one of its criteria which may incorporate this criterion. Similarly, straining that is not accompanied by pain has been suggested for inclusion in future classifications in light of its relatively frequent reporting in constipated children. One recent study in Sri Lanka identified straining in 75% of children with constipation (as defined by both the PACCT and Rome III

Another criticism of PACCT has been that 'large faecal mass in the rectum' (a criteria only ascertained by physical examination or an abdominal radiograph) may be difficult to assess in large community surveys (without the involvement of an assessing clinician) (Maffei and Morais, 2005). There is a strong need to address the applicability and validity of the Rome III diagnostic classification for constipation in both primary care and community settings.

Some of the above concerns were addressed by the 'Boston working group' in their definition of constipation in children (Hyams et al, 2002) (see Table 2). This is another

opinion that the Rome II criteria are too restrictive.

criteria) (Rajindrajith et al., 2009).

diagnostic classification which takes into account that not all constipated children may have infrequent defaecation. It also accounts for the known variation in stool consistency amongst breastfed infants and wide variant of the norm.

The evolution of these diagnostic classifications reflects the complexities of trying to create a system that can be easily understood, reliable, applicable to children in both hospital and community settings and validated by evidence based processes.

### **4. Challenges associated with the diagnosis of constipation in the paediatric population**

The traditional diagnostic approach centres on a thorough history, detailed examination and the use of relevant supporting investigations. This can be challenging in paediatrics requiring utilisation of the 'art' of medicine to take a history from both child and parents, and willingness to modify the examination of the child depending on age and cooperation.

As current definitions of constipation are largely symptom based, the reporting of these symptoms is influenced by an individual's perception of 'the norm'. Studies have shown that parents and children may have different insight into a child's symptoms (Caplan et al., 2005), which may pose a further challenge for clinicians.

### **4.1 Different insight from parents, clinicians and children**

Constipation can be difficult for parents to recognise and they may under-report this condition in their child. There is a difference between parental and clinician recognition of constipation.

One study found that parents tended to under-report constipation in their children (sensitivity 23%) but were good at recognising when their child was not constipated (specificity 90%) (McGrath & Caldwell, 2008). Although parents were able to identify individual symptoms of constipation during history taking, they were poor at recognising that these symptoms signified constipation. Table 4 outlines the recognition of different symptoms of constipation by parents in this cohort. Parents were more likely to report constipation with infrequent defecation and presence of faecal incontinence. There was no significant association between parental reporting of constipation and hard consistency of stools and the presence of straining during defaecation.

Clinicians should carefully question parents and children about individual symptoms of constipation rather than relying on parents to recognise that their child is constipated. Other influential factors that must be addressed in history-taking include whether the child is toilet trained, the ease of toilet training, how 'involved' the parents are in their child's bowel hygiene (i.e. do they still require assistance after defaecation with wiping / redressing) and whether the reporting parent is the primary carer for the child (how much time do they spend attending to the child's daily needs). The use of a stool diary may be of value in improving the reliability of recall of this information.

Despite carefully worded questions during history taking, symptoms of constipation may still be missed secondary to parental misunderstanding. Faecal incontinence may be mistaken by parents as 'poor wiping technique by the child' rather than as a manifestation of underlying constipation. In addition, obstipation (severe persistent constipation) with overflow may present with the passage of soft stools which can be mistaken as diarrhoea or even normal bowel actions.

Parental under-reporting or misunderstanding of symptoms may affect the diagnosis of constipation. Recognition of this common condition may also be affected by unreliable history being given by the child. One study compared reporting of duration of symptoms by child versus parent (supported by dates of medical record documentation or relevant investigations). Children tended to under-report symptom duration (with reports of less than 12 weeks compared with duration of greater than 12 weeks according to parental reporting and documentation). This study also showed a significant disparity between parental and child estimates regarding the frequency of the child's stool symptoms (Schurman et al., 2005). Another study supported similar findings with a low concordance identified between the diagnoses of functional constipation made by parents versus children (Caplan et al., 2005).


\* Statistically significant result (P<0.05)

Table 4. Parental reporting of constipation compared with individual parameters of bowel function assessed by clinician (used with permission from McGrath & Caldwell, 2008).

These studies and discrepancies between parent and child reporting highlight certain issues specific to the paediatric consultation. At the various ages and stages of childhood development, who (parent or child) is the most appropriate history-giver? There is no easy answer to this but there needs to be a balance of input from the parent and child, and children's opinions should always be sought in the process of the consultation.

### **4.2 Treating physicians not familiar with diagnostic criteria**

Despite the common nature of constipation in paediatric practice, recent evidence suggests that there is a degree of variability in the diagnosis of constipation between clinicians at

of underlying constipation. In addition, obstipation (severe persistent constipation) with overflow may present with the passage of soft stools which can be mistaken as diarrhoea or

Parental under-reporting or misunderstanding of symptoms may affect the diagnosis of constipation. Recognition of this common condition may also be affected by unreliable history being given by the child. One study compared reporting of duration of symptoms by child versus parent (supported by dates of medical record documentation or relevant investigations). Children tended to under-report symptom duration (with reports of less than 12 weeks compared with duration of greater than 12 weeks according to parental reporting and documentation). This study also showed a significant disparity between parental and child estimates regarding the frequency of the child's stool symptoms (Schurman et al., 2005). Another study supported similar findings with a low concordance identified between the diagnoses of functional constipation made by parents versus children (Caplan et al., 2005).

**No** 14 (35.9) 130 (56.5) 0.02\* **Yes** 25 (64.1) 100 (43.5)

**No** 13 (33.3) 99 (42.9) 0.3 **Yes** 26 (66.7) 132 (57.1)

**Normal** 25 (64.1) 171 (74.3) 0.4

Table 4. Parental reporting of constipation compared with individual parameters of bowel function assessed by clinician (used with permission from McGrath & Caldwell, 2008).

These studies and discrepancies between parent and child reporting highlight certain issues specific to the paediatric consultation. At the various ages and stages of childhood development, who (parent or child) is the most appropriate history-giver? There is no easy answer to this but there needs to be a balance of input from the parent and child, and

Despite the common nature of constipation in paediatric practice, recent evidence suggests that there is a degree of variability in the diagnosis of constipation between clinicians at

**A few times per week** 21 (53.8) 88 (38.1) 0.03\*

**Parental reporting of no constipation N (%)** 

χ **2 p value** 

**Parental reporting of constipation N (%)** 

**≥ Daily** 16 (41) 140 (60.6)

**Soft** 2 (5.1) 9 (3.9)

**Hard** 12 (30.8) 50 (21.7)

children's opinions should always be sought in the process of the consultation.

**4.2 Treating physicians not familiar with diagnostic criteria** 

**< Weekly** 2 (5.1) 3 (1.3)

even normal bowel actions.

**Parameters of bowel function as assessed by clinician** 

**Soiling (in last 6 months)** 

**Frequency of defecation** 

**Consistency of stools** 

\* Statistically significant result (P<0.05)

**Straining** 

different levels of health care. At a tertiary level, one study demonstrated low inter-rater reliability for diagnosis of constipation by different Paediatric Gastroenterologists (Saps & Di Lorenzo, 2004).

Because of the limitations in defining constipation, it is difficult to ascertain the true prevalence of this problem in different primary health care settings. However, it is a common problem in the primary care setting and the family doctor is often the one who initiates preliminary diagnosis and management. This is particularly the case in settings where a primary carer referral is required prior to seeing a paediatrician or paediatric specialist. Unfortunately some primary care physicians are not aware of current diagnostic classifications and clinical guidelines for managing constipation in children. One study in the USA found that the majority of primary care physicians (67-86%) in West Virginia were not familiar with the published clinical guidelines for constipation in children (Whitlock-Morales et al., 2007).

Further research is needed to assess the understanding of constipation and its management by primary care physicians and the burden of this condition on their clinical practice. Appropriate clinical updates and education should be provided to primary care physicians as early diagnosis and management is associated with better treatment outcomes.

### **5. Suggestions for clinical practice: general approach to the diagnosis of constipation in children**

### **5.1 Clinical history-taking**

A thorough medical history (taken from the parent and child) is paramount in the diagnosis of constipation in children. It helps to identify the problem, quantify its severity and any complications present and recognise any 'red flags' suggestive of an underlying organic condition (see Table 5).

Parents should be asked about passage of meconium in the newborn period as a delay may indicate underlying Hirschsprung's disease, anorectal malformations including imperforate anus or cystic fibrosis. If cystic fibrosis is suspected, one should clarify whether newborn screening testing has taken place and if not, arrange for appropriate investigations to take place. Details should be sought about the onset of the problem including any associated changes in health status, diet or medications at that particular time.

Certain childhood milestones can be associated with the temporal onset of constipation. These include changes in feeding patterns (e.g. wean from breast milk to cow's milk-based formula or to solid foods) and time of toilet training and details of these milestones should be requested. Enquires should be made about any association between the onset of constipation and the commencement of school. Children may 'put off' defecation when they first start school in order to prioritise play or because they find the school toilet environment unfamiliar or unpleasant. These children may exhibit withholding behaviours or retentive posturing (squeezing legs or buttocks together or often appearing 'fidgety').

Information should be sought about previous treatment strategies used including response to treatment. Questions should be asked directly about stool frequency, consistency (with utilisation of the Bristol Stool Chart as a visual aid), size (e.g. whether they obstruct the toilet bowel), shape (are the stools scybalous or pebble-like), straining during bowel movements (both painful and non-painful), feeling of incomplete bowel emptying or any retentive posturing. Details of associated anorectal pain and episodes of rectal bleeding, mucous in stool or faecal incontinence should be sought. In addition, systemic symptoms should be addressed including abdominal pain, anorexia, fever, nausea, vomiting and weight loss.


Table 5. Organic aetiology of constipation (modified from Benninga et al., 2004).

A dietary and activity history should be determined including fluid intake. Questions should be asked about details of the social environment and any life events of note (e.g. birth of a new sibling, parental separation or family death). Suspected misunderstandings or cultural beliefs related to bowel habits should be explored (such as the belief that faecal incontinence with constipation is from poor wiping technique or voluntary). A history of toileting routines should be sought including whether the child uses a potty or an adult toilet and whether foot support is used.

A strong family history of constipation may be of relevance and the presence of any relatives with possible related conditions such as hypothyroidism or coeliac disease should be clarified. It is important to carefully ask about social circumstances and family dynamics. In particular, one should always ensure there are no concerns about child abuse. It is necessary to exclude any underlying organic aetiology by asking about abdominal distension, ano-sacral malformations, scoliosis, lower limb deformities or neuromuscular signs. In light of its association, urinary dysfunction should be addressed. Details should be asked about daytime and night time incontinence, dysuria, urinary frequency or offensive smelling urine.

### **5.2 Physical examination**

A complete physical and neurologic examination is necessary, focussing on the abdomen, the sacral region (assessing for signs of underlying spinal abnormalities such as skin discolouration, naevi, sinuses, hairy patch or central pit) and the perineum (for the presence of anal fissures and to exclude anal malformations). Anal fissures are commonly associated with painful defaecation and may lead to stool withholding behaviours, chronic constipation, stool impaction and eventually faecal incontinence.

The rectal digital examination is no longer performed as a routine part of examination although some clinicians still employ its use. The clinical benefit of performing this procedure (to assess anal sphincter tone and confirm faecal impaction) must be weighed against the physical and psychological discomfort for the child.

### **5.3 Role of Investigations**

A careful history and detailed examination is all that is required for the diagnosis of most children with functional constipation. In certain situations, there may be a role for investigations including abdominal radiography, blood tests for thyroid disease, coeliac disease or hypercalcaemia, anorectal manometry and colonic transit studies; however this is not discussed further in this chapter.

### **6. Conclusion**

14 Constipation – Causes, Diagnosis and Treatment

(both painful and non-painful), feeling of incomplete bowel emptying or any retentive posturing. Details of associated anorectal pain and episodes of rectal bleeding, mucous in stool or faecal incontinence should be sought. In addition, systemic symptoms should be addressed including abdominal pain, anorexia, fever, nausea, vomiting and weight loss.

Unknown

Toxicity

Neoplasia Sexual abuse

Table 5. Organic aetiology of constipation (modified from Benninga et al., 2004).

A dietary and activity history should be determined including fluid intake. Questions should be asked about details of the social environment and any life events of note (e.g. birth of a new sibling, parental separation or family death). Suspected misunderstandings or cultural beliefs related to bowel habits should be explored (such as the belief that faecal incontinence with constipation is from poor wiping technique or voluntary). A history of toileting routines should be sought including whether the child uses a potty or an adult

A strong family history of constipation may be of relevance and the presence of any relatives with possible related conditions such as hypothyroidism or coeliac disease should be clarified. It is important to carefully ask about social circumstances and family dynamics. In particular, one should always ensure there are no concerns about child abuse. It is necessary to exclude any underlying organic aetiology by asking about abdominal distension, ano-sacral malformations, scoliosis, lower limb deformities or neuromuscular signs. In light of its association, urinary dysfunction should be addressed. Details should be asked about daytime and night time incontinence, dysuria, urinary frequency or offensive

A complete physical and neurologic examination is necessary, focussing on the abdomen, the sacral region (assessing for signs of underlying spinal abnormalities such as skin

Slow transit constipation Metabolic, systemic problems:

anticholinergics) Lead poisoning

Psychological problems: Anorexia nervosa Depression

Drugs (opiates, antidepressants,

 Diabetes mellitus Hypothyroidism Hypercalcaemia

**Infants and toddlers Adolescents** 

Unknown

Structural problems: Anal fissures

 Coeliac disease Cystic fibrosis Neuroenteric problems:

 Anorectal malformations Dietary, behavioural problems: Breast feeding to bottle feeding Stool withholding behaviour Cow's milk protein allergy Metabolic, systemic problems:

 Intestinal pseudo-obstruction Hirschsprung's disease Neuronal intestinal dysplasia Spinal cord problems / spina bifida

toilet and whether foot support is used.

smelling urine.

**5.2 Physical examination** 

Constipation is a common childhood problem. It affects children of all ages and is relevant to both primary and tertiary care settings. Early identification and treatment of constipation in children is paramount. It has been associated with better response to treatment and overall outcome. Children will experience less associated complications including physical discomfort, impaired quality of life, faecal incontinence and urinary dysfunction.

A number of different symptom based classifications have been created in an attempt to objectify the diagnosis of constipation and allow for better comparison between studies. These classifications have been compared and contrasted but further studies are needed in order to validate their use and encourage widespread acceptance and application.

The diagnosis of constipation in children can be challenging. Parents, children and clinicians may have different opinions on symptoms and may misdiagnose or under-diagnose this condition. Recognition can be optimised by the use of a thorough history and detailed physical examination. In most children, investigations are not required for diagnosis but they may be indicated in some cases of chronic constipation or constipation that is refractory to treatment.

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treatment in chronically constipated children with encopresis. *Journal of Pediatrics,* 

resolution with treatment of chronic constipation of childhood. *Pediatrics,* Vol. 100,


Youssef, N.N., Langseder, A.L., Verga, B.J., Mones, R.L., & Rosh, J.R. (2005). Chronic childhood constipation is associated with impaired quality of life: a case controlled study. *Journal of Pediatric Gastroenterology and Nutrition,* Vol. 41, No. 1, pp. 56-60.

## **The Role of Diagnostic Tests in Constipation in Children**

Anthony G. Catto-Smith and Kathleen H. McGrath *The Royal Children's Hospital, Melbourne Australia* 

### **1. Introduction**

18 Constipation – Causes, Diagnosis and Treatment

Youssef, N.N., Langseder, A.L., Verga, B.J., Mones, R.L., & Rosh, J.R. (2005). Chronic

childhood constipation is associated with impaired quality of life: a case controlled study. *Journal of Pediatric Gastroenterology and Nutrition,* Vol. 41, No. 1, pp. 56-60.

> The diagnosis of constipation is usually suspected based on the presence of certain symptoms. These may include infrequent passage of stool, stools that are hard or difficult to pass or the presence of faecal incontinence. A careful clinical history and focussed physical examination are often all that is needed to confirm the diagnosis. There are a number of symptom-based classification tools that have been designed for diagnostic use in clinical practice. These classifications have evolved over time but there remains no universally accepted gold standard. The most recently published classification tool is the Rome III classification system.

> In certain situations, further diagnostic investigations may be required to confirm the diagnosis or elicit further details to assist in optimal management of the patient. These investigations may range from simple blood tests or abdominal radiography to more complex measures of colonic transit and function that are only available in specialised centres.

> This chapter will examine, evaluate and define the role of each of these tests using an evidence based approach. It will determine when it is appropriate to do physiological or other testing in constipated children and assist clinicians in selecting the most appropriate modality of investigation for their patients.

### **2. Physiology of defaecation**

The process of defaecation relies upon a complex interplay between pelvic muscles, muscles of the internal and external anal sphincters and the autonomic and somatic nervous systems.

Faecal matter is moved from the colon into the rectum by peristaltic propagation. The presence of faecal matter in the rectum stretches the rectal wall and the puborectalis and levator ani muscles relax. Distension of the rectum induces a parasympathetic response involving contraction of the rectal walls and relaxation of the internal anal sphincter (rectoanal inhibitory reflex).

When faeces enter the anal canal, anal receptors are activated and the voluntary component of the process is initiated. In an appropriate environment and social situation, the external anal sphincter and puborectalis muscle relax and there is simultaneous contraction of the levator ani, abdominal and diaphragm muscles. At this time, defaecation occurs and faecal matter is evacuated from the body.

In instances where the environment or social situation is unsuitable for defaecation to occur, the external anal sphincter voluntarily remains contracted with the help of the pelvic floor muscles. This occurs for a few seconds until the rectal wall is able to adapt and distend to allow for storage of the additional rectal volume.

Some children may achieve voluntary bowel control around the age of 18 months but there is variability in the age of attainment of complete bowel control. Most children will achieve bladder and bowel control and be toilet trained by the age of 3 years.

### **3. Physiology of constipation**

Some children will have an underlying organic cause for their constipation. These children may be identified by the presence of 'red flag' signs on history taking and examination or characteristic findings on diagnostic investigations. The underlying physiological process will differ based on the individual aetiology e.g. Hirschprung disease is caused by absence of enteric nerves and functional obstruction compared with mechanical obstruction in cases of anal stenosis or atresia.

However, in at least 90% of children, there is no underlying organic cause found for constipation and it is termed 'functional constipation'. Withholding behaviour plays an important role in the development of functional constipation in infants, toddlers and young children. These behaviours can originate from an experience of painful defaecation (e.g. related to passage of hard stools or anal fissures), a lack of regular routine with toileting or environmental factors including unfamiliar bathroom environment associated with time of commencement of school.

Withholding behaviours may manifest as grunting or back arching in infants or clenching of the buttocks and repetitive rocking / fidgeting actions in older children. When stool is withheld, the rectal wall adapts and distends to allow for the storage of faecal material. Over time, stool accumulates in the rectum and larger, harder faecal matter is formed, which is then associated with further pain on attempted defaecation. This cycle of persistent painful defaecation can lead to further retentive posturing and toilet avoidance. With time, increasing rectal distension can result in rectal insensitivity and faecal incontinence with a significant impact on the child's quality of life.

### **4. The use of diagnostic tests in constipation in adults**

A recent review summarised the different diagnostic tests available for use in adult constipation (Rao & Meduri, 2011). Using the available evidence, graded recommendations were given for each diagnostic test. These recommendations were based on the presence and quality of evidence in favour of the test in addition to information on specificity, sensitivity, accuracy and predictive values.

Table 1 summarises these findings.

Key:

Grade A1: Excellent evidence in favour of the test based on high specificity, sensitivity, accuracy and positive predictive values.

Grade B2: Good evidence in favour of the test with some evidence on specificity, sensitivity, accuracy and predictive values.

In instances where the environment or social situation is unsuitable for defaecation to occur, the external anal sphincter voluntarily remains contracted with the help of the pelvic floor muscles. This occurs for a few seconds until the rectal wall is able to adapt and distend to

Some children may achieve voluntary bowel control around the age of 18 months but there is variability in the age of attainment of complete bowel control. Most children will achieve

Some children will have an underlying organic cause for their constipation. These children may be identified by the presence of 'red flag' signs on history taking and examination or characteristic findings on diagnostic investigations. The underlying physiological process will differ based on the individual aetiology e.g. Hirschprung disease is caused by absence of enteric nerves and functional obstruction compared with mechanical obstruction in cases

However, in at least 90% of children, there is no underlying organic cause found for constipation and it is termed 'functional constipation'. Withholding behaviour plays an important role in the development of functional constipation in infants, toddlers and young children. These behaviours can originate from an experience of painful defaecation (e.g. related to passage of hard stools or anal fissures), a lack of regular routine with toileting or environmental factors including unfamiliar bathroom environment associated with time of

Withholding behaviours may manifest as grunting or back arching in infants or clenching of the buttocks and repetitive rocking / fidgeting actions in older children. When stool is withheld, the rectal wall adapts and distends to allow for the storage of faecal material. Over time, stool accumulates in the rectum and larger, harder faecal matter is formed, which is then associated with further pain on attempted defaecation. This cycle of persistent painful defaecation can lead to further retentive posturing and toilet avoidance. With time, increasing rectal distension can result in rectal insensitivity and faecal incontinence with a

A recent review summarised the different diagnostic tests available for use in adult constipation (Rao & Meduri, 2011). Using the available evidence, graded recommendations were given for each diagnostic test. These recommendations were based on the presence and quality of evidence in favour of the test in addition to information on specificity,

Grade A1: Excellent evidence in favour of the test based on high specificity, sensitivity,

Grade B2: Good evidence in favour of the test with some evidence on specificity, sensitivity,

allow for storage of the additional rectal volume.

**3. Physiology of constipation** 

of anal stenosis or atresia.

commencement of school.

significant impact on the child's quality of life.

sensitivity, accuracy and predictive values.

accuracy and positive predictive values.

Table 1 summarises these findings.

accuracy and predictive values.

Key:

**4. The use of diagnostic tests in constipation in adults** 

bladder and bowel control and be toilet trained by the age of 3 years.

Grade B3: Fair evidence in favour of the test with some evidence on specificity, sensitivity, accuracy and predictive values.

Grade C: Poor evidence in favour of the test with some evidence on specificity, sensitivity, accuracy and predictive values.


Table 1. Summary of diagnostic tests and their recommended grade in adults (modified from Rao & Meduri, 2011).

Table 1 illustrates the variability in the quality of evidence supporting the use of investigations in the diagnosis of adult constipation. In practice, the diagnosis of constipation still relies heavily on careful history-taking and detailed clinical examination technique.

To date, there are limited studies assessing the role of diagnostic tests in constipation in children. A review by Baker and colleagues in 1999graded the quality of evidence for limited investigations in children using methods of the Canadian Preventive Services Task Force. They found that the evidence for abdominal radiography, when interpreted carefully was II-2 (\*evidence obtained from well-designed cohort or case-control analytic studies, preferably more than one centre or research group). The evidence for rectal biopsy and rectal manometry in reliable exclusion of Hirschprung disease was II-1 (evidence obtained from well-designed cohort or case-control trials without randomisation). Measurement of transit time using radiopaque markers was graded as II-2\* (Baker et al., 1999).

There is limited availability of a supportive consensus guideline for choice of diagnostic tests in children with constipation. This makes the selection of investigations and their interpretation a challenge for many clinicians. This chapter aims to assess the data available with particular focus on the paediatric population group. It outlines both the benefits and limitations of each individual technique to allow clinicians to make an informed decision about when to employ their use.

### **5. The role of radiography**

### **5.1 Abdominal radiography**

The diagnosis of constipation is usually a clinical decision based on good history-taking and physical examination of the child. In clinical practice, abdominal radiography is still performed by some clinicians as part of their initial diagnostic assessment or as a tool to assess and monitor treatment response. There may be a role for abdominal radiography in certain circumstances and these will be discussed below.

Abdominal radiography may be indicated when the diagnosis of chronic constipation is strongly suspected but in doubt because of a lack of supportive evidence on history or examination. In particular, supportive physical signs (in the form of palpable abdominal faecal masses) may be difficult to elicit in obese children or children who have been frequently using stool softeners. Faecal impaction can be suspected clinically and is usually able to be confirmed by rectal examination. However, there may be exceptions where despite a strong suspicion of chronic constipation, there is no palpable faecal retention on rectal examination. The clinical practice guideline of the North American Society for Pediatric Gastroenterology and Nutrition recommends the use of a plain abdominal radiograph for diagnosing constipation in cases where there is uncertainty about the presence of constipation.

Rectal examination is an invasive procedure. Consequently, in some children it may be contraindicated (e.g. in the presence of a history of previous sexual abuse or by the degree of associated psychological distress and angst it causes the child). In these children there may be a role for abdominal radiography in place of a rectal examination to confirm faecal impaction and exclude bowel obstruction prior to the commencement of bowel washout.

Abdominal radiography can be employed in the different circumstances described above. It may also be useful to give a measure of megarectum. The benefits of abdominal radiography include that it is an easily accessible, non-invasive and relatively inexpensive investigation. However, this modality does have some limitations that need to be factored in when it is being considered. Every radiograph performed provides the child with a small dose of ionizing radiation. In isolation, this is unlikely to have direct impact on their wellbeing, but cumulative doses of radiation may be potentially harmful for an individual's health.

The interpretation of abdominal radiography is variable. It has traditionally been largely subjective and open to individual interpretation. In an attempt to objectify the classification of this tool, a number of different scoring systems have been created including the Leech and Barr scoring systems. The Leech score assesses the large intestine in 3 segments: right colon, left colon and rectosigmoid colon and provides a score from 0 to 5 for each segment based on the amount of faeces present (0= no faeces visible to 5= severe faecal loading with bowel dilatation). An overall score out of 15 is obtained, with a score of 9 or greater being positive for constipation. The Barr score divides the large intestine into 4 segments: ascending colon, transverse colon, descending colon and rectum. It quantifies both the amount and consistency of the faeces (e.g. granular, rock-like) and gives a score out of 22 with a score of 10 or greater being positive for constipation (Pensabene et al., 2010).

Despite these formalised classification systems, studies comparing different scoring methods show that there is still a degree of inter-observer variability. This applies to interpretation by both paediatric clinicians and radiologists. Overall, individual scoring systems used for interpretation of faecal loading on abdominal radiograph have a low sensitivity (Pensabene et al., 2010).

A recent systematic review assessed the relationship between clinical symptoms and signs of constipation and the presence of faecal loading on abdominal radiography. The availability of good quality literature was limited, however the study concluded that conflicting evidence exists for an association between the clinical and radiographic diagnosis of constipation. The high quality studies that were assessed in the review found that a radiographic diagnosis of constipation occurs almost as often in clinically constipated children as in clinically non-constipated children. Furthermore, they found that the results of rectal examination were not consistently associated with the presence of fecal retention on abdominal radiography. The review concluded that there is inadequate evidence to support the North American Society for Pediatric Gastroenterology and Nutrition clinical practice guideline and those clinicians who recommend a plain abdominal radiograph in cases of uncertainty of the presence of constipation in a child (Reuchlin-Vroklage LM et al., 2005).

There is a clear need for further clinical research to assess the precise role of abdominal radiography in the diagnosis of constipation in children. Current data provides conflicting opinion and challenging interpretation for clinicians. A better availability of future quality literature shall help to determine the indications for this investigation and validate its use in clinical practice.

### **5.2 Contrast radiography**

### **5.2.1 Barium enema**

22 Constipation – Causes, Diagnosis and Treatment

The diagnosis of constipation is usually a clinical decision based on good history-taking and physical examination of the child. In clinical practice, abdominal radiography is still performed by some clinicians as part of their initial diagnostic assessment or as a tool to assess and monitor treatment response. There may be a role for abdominal radiography in

Abdominal radiography may be indicated when the diagnosis of chronic constipation is strongly suspected but in doubt because of a lack of supportive evidence on history or examination. In particular, supportive physical signs (in the form of palpable abdominal faecal masses) may be difficult to elicit in obese children or children who have been frequently using stool softeners. Faecal impaction can be suspected clinically and is usually able to be confirmed by rectal examination. However, there may be exceptions where despite a strong suspicion of chronic constipation, there is no palpable faecal retention on rectal examination. The clinical practice guideline of the North American Society for Pediatric Gastroenterology and Nutrition recommends the use of a plain abdominal radiograph for diagnosing constipation in cases

Rectal examination is an invasive procedure. Consequently, in some children it may be contraindicated (e.g. in the presence of a history of previous sexual abuse or by the degree of associated psychological distress and angst it causes the child). In these children there may be a role for abdominal radiography in place of a rectal examination to confirm faecal impaction and exclude bowel obstruction prior to the commencement of bowel washout.

Abdominal radiography can be employed in the different circumstances described above. It may also be useful to give a measure of megarectum. The benefits of abdominal radiography include that it is an easily accessible, non-invasive and relatively inexpensive investigation. However, this modality does have some limitations that need to be factored in when it is being considered. Every radiograph performed provides the child with a small dose of ionizing radiation. In isolation, this is unlikely to have direct impact on their wellbeing, but cumulative

The interpretation of abdominal radiography is variable. It has traditionally been largely subjective and open to individual interpretation. In an attempt to objectify the classification of this tool, a number of different scoring systems have been created including the Leech and Barr scoring systems. The Leech score assesses the large intestine in 3 segments: right colon, left colon and rectosigmoid colon and provides a score from 0 to 5 for each segment based on the amount of faeces present (0= no faeces visible to 5= severe faecal loading with bowel dilatation). An overall score out of 15 is obtained, with a score of 9 or greater being positive for constipation. The Barr score divides the large intestine into 4 segments: ascending colon, transverse colon, descending colon and rectum. It quantifies both the amount and consistency of the faeces (e.g. granular, rock-like) and gives a score out of 22

with a score of 10 or greater being positive for constipation (Pensabene et al., 2010).

Despite these formalised classification systems, studies comparing different scoring methods show that there is still a degree of inter-observer variability. This applies to interpretation by both paediatric clinicians and radiologists. Overall, individual scoring

**5. The role of radiography 5.1 Abdominal radiography** 

certain circumstances and these will be discussed below.

where there is uncertainty about the presence of constipation.

doses of radiation may be potentially harmful for an individual's health.

A barium enema (lower gastrointestinal series) is a diagnostic procedure where opaque contrast medium (barium sulfate) is infused into the colon via a rectal enema tube. The flow of barium sulfate is captured by using fluoroscope xray pictures. The patient may be asked to move into different positions to obtain optimal detailed anatomical images of the gastrointestinal tract.

Barium enema can be useful in some instances for the identification of anatomical abnormalities including megacolon, megarectum or rectal masses. It may also be used as an initial screening for Hirschsprung's Disease (a condition characterised by the absence of ganglion cells in the myenteric plexus of the distal colon). The visualisation of a transition radiographic zone and delayed barium emptying is suggestive of Hirschsprung's Disease however not diagnostic. A rectal biopsy is still required to confirm this diagnosis. In neonates, the absence of a transition zone may be a normal variant making this test less useful in this particular age group.

Limitations associated with this modality include associated radiation exposure and the invasive nature of the procedure (requiring placement of an enema tube into the rectum).

Barium enema has little or no role as a routine investigation in the workup of children with chronic constipation but may be used to assess gastrointestinal anatomy in some patients.

### **5.2.2 Defaecating proctography**

Defaecating proctography assesses the mechanics of defaecation in real time using fluoroscopy. A barium paste is manually infused into the rectum using specialised equipment until there is adequate distension. The patient then moves to a portable plastic commode and their process of defaecation is recorded by an x-ray camera.

Defaecating proctography is not commonly performed in current practice. It may have a limited role in assessment of pelvic floor dysfunction (including anismus) in obstructed defaecation. Its main limitations include associated radiation exposure and invasive nature of the procedure.

### **6. The role of blood tests**

Any child undergoing assessment for chronic functional or intractable constipation should have certain blood tests done to exclude an underlying organic cause. This is particularly the case where there are clinical signs or symptoms present that are suggestive of an underlying metabolic or pathological process.

Patients should undergo a complete blood count and biochemical profile, in particular looking at serum calcium levels to exclude hypercalcemia and blood glucose levels to look for evidence of diabetes. Thyroid function tests should be done to exclude hypothyroidism and a coeliac screen and total IgA to assess for evidence of coeliac disease. A diagnosis of coeliac disease can only be confirmed by endoscopy and small intestinal biopsy.

Less commonly, measurement of blood lead levels may be indicated to exclude lead toxicity as an aetiological factor.

### **7. The role of ultrasound**

Ultrasound scan is a safe, non invasive and easily accessible mode of imaging. It is not currently widely utilised in children with constipation, but has a potential role in quantifying the degree of faecal loading / megarectum and monitoring of treatment response.

#### **7.1 Pelvic ultrasound**

Pelvic ultrasound scan can be used to visualise faeces of both hard and soft consistency. One group in the United Kingdom have successfully used pelvic ultrasound together with a scoring system in their outpatient management of constipated children since 2007 (Lakshminarayanan B et al., 2008). Their findings showed that the presence of faecal loading on ultrasound correlated highly with clinical symptoms of constipation on history taking. In addition, of the 269 patients (54%) with no palpable faeces on clinical abdominal examination, 31% of them showed significant faecal loading on ultrasound. This finding supports the notion that despite a thorough history and physical examination, some patients with constipation may still be missed. In patients in whom there remains an ongoing clinical suspicion of constipation, there may be a role for investigations such as ultrasound scan. Lakshminarayanan and colleagues successfully illustrated the use of this modality to diagnose and monitor treatment response of their patients in outpatient clinical practice.

Other studies have attempted to quantify the degree of constipation by using rectal diameter and other measurements on ultrasound scan (Karaman et al., 2010; Joensson et al., 2008). These groups found that a thicker mean rectal diameter correlated with a clinical diagnosis of constipation by Rome III criteria. Furthermore, they found that the amount of faecal loading on ultrasound decreased by a significant amount after one month of treatment supporting a role for this modality in monitoring of treatment response.

Karaman and colleagues could identify no inter-observer difference between 2 different radiologists performing the ultrasound scans. This supports a degree of reliability between different users of ultrasound scan as an imaging modality. Further detailed studies to assess for inter-observer differences between paediatric clinicians and radiologists interpreting ultrasound in this context would be useful.

Pelvic ultrasound is appropriate for use in the outpatient setting. It has no associated radiation dose. It is a non-invasive procedure and in the hands of experienced staff, tends to be well tolerated by children. There are only limited studies available on the use of pelvic ultrasound in constipated children and further research would be beneficial to help ascertain the precise role for this modality in the assessment and long term monitoring of this patient group.

### **7.2 Endoanal ultrasound**

24 Constipation – Causes, Diagnosis and Treatment

equipment until there is adequate distension. The patient then moves to a portable plastic

Defaecating proctography is not commonly performed in current practice. It may have a limited role in assessment of pelvic floor dysfunction (including anismus) in obstructed defaecation. Its main limitations include associated radiation exposure and invasive nature

Any child undergoing assessment for chronic functional or intractable constipation should have certain blood tests done to exclude an underlying organic cause. This is particularly the case where there are clinical signs or symptoms present that are suggestive of an underlying

Patients should undergo a complete blood count and biochemical profile, in particular looking at serum calcium levels to exclude hypercalcemia and blood glucose levels to look for evidence of diabetes. Thyroid function tests should be done to exclude hypothyroidism and a coeliac screen and total IgA to assess for evidence of coeliac disease. A diagnosis of

Less commonly, measurement of blood lead levels may be indicated to exclude lead toxicity

Ultrasound scan is a safe, non invasive and easily accessible mode of imaging. It is not currently widely utilised in children with constipation, but has a potential role in quantifying the degree of faecal loading / megarectum and monitoring of treatment

Pelvic ultrasound scan can be used to visualise faeces of both hard and soft consistency. One group in the United Kingdom have successfully used pelvic ultrasound together with a scoring system in their outpatient management of constipated children since 2007 (Lakshminarayanan B et al., 2008). Their findings showed that the presence of faecal loading on ultrasound correlated highly with clinical symptoms of constipation on history taking. In addition, of the 269 patients (54%) with no palpable faeces on clinical abdominal examination, 31% of them showed significant faecal loading on ultrasound. This finding supports the notion that despite a thorough history and physical examination, some patients with constipation may still be missed. In patients in whom there remains an ongoing clinical suspicion of constipation, there may be a role for investigations such as ultrasound scan. Lakshminarayanan and colleagues successfully illustrated the use of this modality to diagnose and monitor treatment response of their patients in outpatient clinical practice.

Other studies have attempted to quantify the degree of constipation by using rectal diameter and other measurements on ultrasound scan (Karaman et al., 2010; Joensson et al., 2008). These groups found that a thicker mean rectal diameter correlated with a clinical diagnosis

coeliac disease can only be confirmed by endoscopy and small intestinal biopsy.

commode and their process of defaecation is recorded by an x-ray camera.

of the procedure.

**6. The role of blood tests** 

metabolic or pathological process.

as an aetiological factor.

**7.1 Pelvic ultrasound** 

response.

**7. The role of ultrasound** 

Endoanal ultrasound involves insertion of an ultrasound probe into the anus allowing visualisation of the internal sphincter, external sphincter and puborectalis muscles. It can be used to provide information about the anatomical course of anal fistulae and some anal abscesses.

Endoanal ultrasound is relatively quick and simple to perform. There is no associated radiation dose. In some children it may not be well tolerated due to its invasive nature and may require the use of sedation or general anaesthetic in order to perform effectively. In addition, patients must undergo an enema a few hours beforehand to ensure adequate clearance of the rectal area prior to scanning.

### **8. The role of gastrointestinal transit studies**

Colonic transit studies have traditionally provided information about total and segmental colonic transit time and overall colorectal motor function. There are 2 standard techniques performed: radio-opaque marker studies and radio-nuclide scintigraphy. Both techniques give similar information for ascending and transverse colon motility but radio-opaque marker studies generally produce faster total transit time (Southwell et al., 2009).

Colonic transit studies classify children with constipation into 3 subgroups:


Colonic transit studies can be used to differentiate slow-transit constipation from pelvic dyssynergia. In clinical practice, this information can be useful to identify patients with motility disorders including Hirschsprung's disease and chronic intestinal pseudoobstruction. It can also be used to help differentiate children with functional constipation and overflow incontinence from those with nonretentive faecal incontinence (Benninga et al. 1994). This is important as management differs between the two conditions.

Colonic transit studies may also have a role in predicting patient prognosis. One study showed a colon transit time of > 100 hours was associated with a poor treatment outcome at one year (de Lorijn et al., 2004). The range of normal colonic transit is 20-56 hours and there is little variation between children and adults (Southwell et al., 2009).

A more recent innovation is the use of wireless capsule technology. The additional benefits of radio-nuclide scintigraphy and wireless capsule monitoring are their capacity to give information about gastrointestinal transit in the stomach and small intestine as well as the colon. In cases of severe refractory constipation, this data may be useful in pre-operative assessment to aid decision-making about the portion of bowel for resection and the best position(s) for stoma creation. Information on gastric and small intestinal motility may also be useful in children with abnormal gastric emptying to help decide on appropriate methods of feeding (e.g. gastrostomy versus jejunostomy feeds).

### **8.1 Radio-opaque marker studies**

This technique was first pioneered in adults in the late 1960s. There are a number of variations in its application including a few more commonly used methods. Firstly, there is the 'simple' radio-opaque marker test where a single capsule is swallowed (containing 20-50 markers) and a single abdominal radiograph is taken 4-5 days later showing the location of the markers. Alternatively, a single capsule (containing multiple markers) is ingested and radiographs are performed every 24 hours until the markers are no longer visible. A third technique is the 'multiple markers' test where a single capsule is ingested daily for 3 days (each containing a different shaped marker) and abdominal radiographs are taken at days 4 and 7 after ingestion. The different marker shapes help to identify their individual locations.

Delayed transit is defined as retention of more than 20% of markers at the time of abdominal radiograph (96 hours for the 'simple' test and 120 hours for the 'multiple markers' test) (Dinning and Di Lorenzo, 2011). Children should refrain from taking laxatives in the weeks before the study as these may affect bowel function and subsequent results.

Radio-opaque marker studies are inexpensive, relatively widely available and are useful in the identification of slow transit constipation. Their downside is the associated variability with the use of different methodologies and the lack of information gained regarding transit in the rest of the gastrointestinal tract.

### **8.2 Radio-nuclide scintigraphy**

Radio-nuclide scintigraphy has been utilised since the mid 1980s. It involves oral ingestion of a labelled isotope followed by gamma camera scans at various intervals up to 5 days (depending on the specific method used). The progression of the isotope throughout colonic regions is plotted using graphs. It is possible to calculate the amount of isotope residue at each region for each time interval. Various measures of isotope retention can be used to diagnose and quantify delayed colonic transit. There include transit time in hours, % radioactivity retained, proximal colonic emptying and centre of mass.

Radio-nuclide scintigraphy is expensive and requires an appropriately equipped and trained specialist centre which may not be readily accessible to all clinicians. In addition, results of different studies may not be directly comparable due to differences in the method of isotope administration (e.g. liquid verus solid markers) and varying measurements of interpretation used. However, radio-nuclide scintigraphy can be useful for classification of pathophysiological subtypes of constipation as outlined in the introduction to section 6.

### **8.3 Wireless capsule technology**

26 Constipation – Causes, Diagnosis and Treatment

Colonic transit studies may also have a role in predicting patient prognosis. One study showed a colon transit time of > 100 hours was associated with a poor treatment outcome at one year (de Lorijn et al., 2004). The range of normal colonic transit is 20-56 hours and there

A more recent innovation is the use of wireless capsule technology. The additional benefits of radio-nuclide scintigraphy and wireless capsule monitoring are their capacity to give information about gastrointestinal transit in the stomach and small intestine as well as the colon. In cases of severe refractory constipation, this data may be useful in pre-operative assessment to aid decision-making about the portion of bowel for resection and the best position(s) for stoma creation. Information on gastric and small intestinal motility may also be useful in children with abnormal gastric emptying to help decide on appropriate

This technique was first pioneered in adults in the late 1960s. There are a number of variations in its application including a few more commonly used methods. Firstly, there is the 'simple' radio-opaque marker test where a single capsule is swallowed (containing 20-50 markers) and a single abdominal radiograph is taken 4-5 days later showing the location of the markers. Alternatively, a single capsule (containing multiple markers) is ingested and radiographs are performed every 24 hours until the markers are no longer visible. A third technique is the 'multiple markers' test where a single capsule is ingested daily for 3 days (each containing a different shaped marker) and abdominal radiographs are taken at days 4 and 7 after ingestion. The different marker shapes help to identify their individual locations. Delayed transit is defined as retention of more than 20% of markers at the time of abdominal radiograph (96 hours for the 'simple' test and 120 hours for the 'multiple markers' test) (Dinning and Di Lorenzo, 2011). Children should refrain from taking laxatives in the weeks

Radio-opaque marker studies are inexpensive, relatively widely available and are useful in the identification of slow transit constipation. Their downside is the associated variability with the use of different methodologies and the lack of information gained regarding transit

Radio-nuclide scintigraphy has been utilised since the mid 1980s. It involves oral ingestion of a labelled isotope followed by gamma camera scans at various intervals up to 5 days (depending on the specific method used). The progression of the isotope throughout colonic regions is plotted using graphs. It is possible to calculate the amount of isotope residue at each region for each time interval. Various measures of isotope retention can be used to diagnose and quantify delayed colonic transit. There include transit time in hours, %

Radio-nuclide scintigraphy is expensive and requires an appropriately equipped and trained specialist centre which may not be readily accessible to all clinicians. In addition, results of different studies may not be directly comparable due to differences in the method

is little variation between children and adults (Southwell et al., 2009).

methods of feeding (e.g. gastrostomy versus jejunostomy feeds).

before the study as these may affect bowel function and subsequent results.

radioactivity retained, proximal colonic emptying and centre of mass.

**8.1 Radio-opaque marker studies** 

in the rest of the gastrointestinal tract.

**8.2 Radio-nuclide scintigraphy** 

This is a relatively recent innovation. It involves an ingestible gastrointestinal capsule, a receiver worn by the patient during the study period, a receiver docking station and display software. The capsule is able to identify and transmit information about intraluminal pH, pressure and temperature and has a battery life of 5 days.

To date, there are no large studies looking at the use of wireless capsule technology in children and little clinical experience from clinical application in this population group. Limited research available in adult patients has compared wireless capsule assessment of gastrointestinal motility with radio-nuclide scintigraphy. A recent study performed simultaneous whole gut scintigraphy and wireless capsule monitoring of whole gut transit in 10 adults. They found a very strong correlation between measurements of gastric emptying by the two different methods (Maqbool et al, 2009).

Potential benefits of this technique include no associated radiation exposure and its capacity to provide information about stomach and small intestine transit as well as colonic transit (by its ability to monitor pH and thus detect progression from the stomach into the small intestine).

In children, this technique may have some limitations. It relies upon the ingestion of a wireless capsule which some younger children may find difficult or unappealing. An alternative option is placement of the capsule into the stomach at the time of an endoscope.

This technique is relatively new to clinical practice and further studies are needed to elucidate its precise role in the investigation of children with constipation.

### **9. Manometric studies**

Manometry involves the measurement of pressures in various segments of the gastrointestinal tract to provide information on gastrointestinal function and motility. Both water perfused and solid state catheters have been used.

### **9.1 Anorectal manometry**

Anorectal manometry assesses the motor function of the anal sphincters, sensory thresholds to rectal distension, recto-anal inhibitory reflexes and coordination of evacuation. Some degree of bowel preparation is required beforehand. A transducer is inserted through the anus with the child in the left lateral position and a sphincter pressure profile measured. Transient inflation of a balloon at the tip of the catheter assembly allows measurement of sensory thresholds, and also confirms normal reflex relaxation of the internal anal sphincter (rectoanal inhibitory reflex). Attempted evacuation of the rectal balloon allows examination of the normal coordination of evacuation as well as the response to withholding (squeezing).

Anorectal manometry is useful to exclude sphincteric damage, and rule out Hirschsprung disease. Blunted sensation to rectal distension and megarectum can also be defined.

Anorectal manometry also has a role in the identification of dyssynergic defaecation and altered rectal sensation in children with constipation (Rao et al., 2011). The normal process of defaecation involves relaxation of the puborectalis muscle and external anal sphincter combined with an adequate propulsive force. Pelvic floor dyssynergia occurs when there is abnormal pelvic floor muscle relaxation or even paradoxical contraction during the process of attempted defaecation. These children are unable to produce the coordination required for normal defaecation and frequently become constipated.

Identification of dyssynergic defaecation is important as it changes management intervention. These children do not require laxative management but will benefit from behavioural interventions and possibly from the use of biofeedback therapy (Chiarioni et al., 2006). Biofeedback therapy is a method of neuromuscular re-education. A computer and video monitor are used to display bodily processes to a patient that they are normally unaware of. Increased awareness of these behaviours provides an opportunity to consciously modify one's responses to a more acceptable pattern.

The most common problem associated with the use of anorectal manometry is that it is limited to certain specialised centres. Other complications may include a lack of standardisation in technique between different transducers and technical errors related to inadequate balloon sufflation or positioning (Benninga et al., 2004).

Anorectal manometry provides information on pathophysiological abnormalities underlying childhood constipation.

### **9.1.1 Rectal barostat test**

The rectal barostat test consists of a highly compliant balloon placed in the rectum and connected to a barostat (computerised pressure-distending device). This device is able to record detailed information on tone, compliance and assess rectal sensation.

The information obtained by this technique can be useful in identification of megarectum, hyper- or hypo- compliant rectum. Rectal compliance, sensation and function are all closely inter-related.

### **9.2 Colonic manometry**

Colonic manometry provides a detailed picture of overall motor activity of the colon. The American Neurogastroenterology and Motility Society recently recommended its use in assessment of severely constipated children unresponsive to medical therapy, with evidence of slow colonic transit and the absence of an evacuatory disorder (Camilleri et al., 2008). It can be also be used to differentiate functional constipation from constipation secondary to an underlying neuromuscular cause.

On study looked at the indications for colonic manometry in a group of 146 children referred to a tertiary centre in the USA (Pensabene et al., 2003). The 4 main indications identified for use of colonic manometry were:


Anorectal manometry also has a role in the identification of dyssynergic defaecation and altered rectal sensation in children with constipation (Rao et al., 2011). The normal process of defaecation involves relaxation of the puborectalis muscle and external anal sphincter combined with an adequate propulsive force. Pelvic floor dyssynergia occurs when there is abnormal pelvic floor muscle relaxation or even paradoxical contraction during the process of attempted defaecation. These children are unable to produce the coordination required

Identification of dyssynergic defaecation is important as it changes management intervention. These children do not require laxative management but will benefit from behavioural interventions and possibly from the use of biofeedback therapy (Chiarioni et al., 2006). Biofeedback therapy is a method of neuromuscular re-education. A computer and video monitor are used to display bodily processes to a patient that they are normally unaware of. Increased awareness of these behaviours provides an opportunity to

The most common problem associated with the use of anorectal manometry is that it is limited to certain specialised centres. Other complications may include a lack of standardisation in technique between different transducers and technical errors related to

Anorectal manometry provides information on pathophysiological abnormalities

The rectal barostat test consists of a highly compliant balloon placed in the rectum and connected to a barostat (computerised pressure-distending device). This device is able to

The information obtained by this technique can be useful in identification of megarectum, hyper- or hypo- compliant rectum. Rectal compliance, sensation and function are all closely

Colonic manometry provides a detailed picture of overall motor activity of the colon. The American Neurogastroenterology and Motility Society recently recommended its use in assessment of severely constipated children unresponsive to medical therapy, with evidence of slow colonic transit and the absence of an evacuatory disorder (Camilleri et al., 2008). It can be also be used to differentiate functional constipation from constipation secondary to

On study looked at the indications for colonic manometry in a group of 146 children referred to a tertiary centre in the USA (Pensabene et al., 2003). The 4 main indications

2. Clarification of pathophysiology of persisting lower gastrointestinal symptoms after

1. Clarification of pathophysiology of lower gastrointestinal symptoms (68%)

for normal defaecation and frequently become constipated.

consciously modify one's responses to a more acceptable pattern.

inadequate balloon sufflation or positioning (Benninga et al., 2004).

record detailed information on tone, compliance and assess rectal sensation.

underlying childhood constipation.

**9.1.1 Rectal barostat test** 

**9.2 Colonic manometry** 

an underlying neuromuscular cause.

identified for use of colonic manometry were:

surgery for Hirschsprung's Disease (14%)

inter-related.


Colonic manometry is performed by using colonic catheters that incorporate multiple recording ports or sensors. These provide a feedback of information on intraluminal pressures to a recording system. The catheters can be water-perfused or solid state, with most paediatric centres favouring the former (Dinning PG & Di Lorenzo C, 2011). Catheters are usually placed by colonoscope or via radiological guidance such as fluoroscopy after adequate colonic clearance using bowel preparation. They can be placed into the mouth, nose, anus (most common) or through an existing stoma. The study period generally lasts around 5 hours but may be up to 24 hours in duration.

Water-perfused catheters consist of flexible tubing with multiple recording ports connected to a pneumohydraulic infusion pump that provides a constant flow of water. Colonic wall contractions occlude the ports and impede water flow and this resistance to flow is transmitted as pressure change to external transducers. These catheters are relatively cost effective and some are autoclaveable and re-usable. On the downside, patients are confined to bed for the duration of the study and uncertainty exists regarding whether large amounts of infused water may have deleterious effects in young children (Dinning et al., 2010).

Solid-state catheters comprise strain gauges embedded into a flexible tube. Each gauge connects to a recording system by fine wiring. Used with portable recorders, these catheters allow the patient to be ambulant because they don't rely on constant water flow. However they do tend to be more expensive than water-perfused catheters (Dinning et al., 2010).

There are 2 types of normal colonic motor activity:


In addition, colonic motility should increase after a meal (gastro-colonic response) and respond to other physiological stimuli such as morning waking and exercise (Hussain SZ & Di Lorenzo C, 2002). The presence of these features of normal colonic motility in the context of constipation suggests a behavioural cause or functional constipation.

In the case of abnormalities, colonic manometry can distinguish between an underlying neuropathy and myopathy. Weak or absent colonic contractions in the absence of generalised colonic dilatation suggests a colonic myopathy. Absent, disordered or abnormal colonic contractions combined with an absent gastro-colonic meal response suggests the presence of an underlying neuropathy.

Colonic manometry may also have a role in monitoring of treatment response in constipation management. A study by Pensabene et al in 2003 showed that the results of colonic manometry resulted in recommendations to adjust management plans (mostly surgical intervention) in 93% of 146 children. Of the 98 patients that were able to be contacted for follow up data, 88% had parents who believed that these interventions had been a positive impact on their child's health.

Colonic manometry is a useful diagnostic tool in childhood chronic constipation and a number of international centres are trained in this technique. Compared with adults, there are less underlying systemic diseases or drugs affecting colonic motility in children and the results tend to be easier to interpret in this younger population.

Limitations related to this diagnostic procedure include variation related to use of different catheter types, placement techniques and protocols in different centres. It is also associated with a degree of invasiveness and so may not be tolerated well by some children.

### **10. Electromyography**

Electromyography records the electrical activity of skeletal muscles and can be used to assess for evidence of abnormal skeletal muscle function. Combined with manometry, it can be useful to confirm the presence of paradoxical sphincteric contraction during attempted defaecation.

### **11. The role of biopsy**

The most common biopsy performed in relation to childhood constipation is a rectal biopsy. This is done in cases of suspected Hirschsprung's disease to confirm a diagnosis. The child may or may not have had other previous investigations including barium enema or anal manometry.

Usually a suction-method biopsy is performed. This is a simple and quick procedure, though does carry a risk for haemorrhage. In neonates, it can be performed at the bedside without the need for a general anaesthetic. Occasionally there may be difficulty obtaining an adequate tissue specimen by this technique (as it is a blind procedure). In these circumstances, a full thickness surgical biopsy may need to be performed.

There may be a role for other gastrointestinal tract biopsies to demonstrate abnormal histology in the presence of chronic constipation (e.g. neuronal intestinal dysplasia: qualitative and quantitative abnormalities of the myenteric plexus).

### **12. Magnetic Resonance Imaging**

Magnetic resonance imaging (MRI) of the spine may be performed in children with constipation if the patient history or physical examination is suggestive of spinal pathology. A recent study looked at the result of MRI-spine scans performed on 88 children with intractable constipation. They found that 9% (8 children) had spinal abnormalities on MRI that required surgery (75% of these were a tethered cord). Of these 8 children, 5 had no abnormal signs on physical examination. (Rosen et al., 2004). This study highlights the importance of a thorough history and physical examination in any child presenting with chronic constipation. In particular, one should assess the lower limb neurological status and sacral area for any abnormalities (skin discolouration, naevi, sinuses, hairy patch, central pit or bony abnormalities).

MRI and MR defecography (dynamic pelvic MRI) have also been used in the assessment of anorectal disorders. They have the advantage of being able to simultaneously image anatomy and motility function and a low dosage of radiation exposure. However, there is a high associated cost and very limited data exists on the role of this investigation in children.

### **13. Miscellaneous Investigations**

There are some other investigations that may be indicated in assessment for underlying causes in chronic constipation. These include the following:


### **14. Conclusion**

30 Constipation – Causes, Diagnosis and Treatment

Limitations related to this diagnostic procedure include variation related to use of different catheter types, placement techniques and protocols in different centres. It is also associated

Electromyography records the electrical activity of skeletal muscles and can be used to assess for evidence of abnormal skeletal muscle function. Combined with manometry, it can be useful to confirm the presence of paradoxical sphincteric contraction during attempted

The most common biopsy performed in relation to childhood constipation is a rectal biopsy. This is done in cases of suspected Hirschsprung's disease to confirm a diagnosis. The child may or may not have had other previous investigations including barium enema or anal

Usually a suction-method biopsy is performed. This is a simple and quick procedure, though does carry a risk for haemorrhage. In neonates, it can be performed at the bedside without the need for a general anaesthetic. Occasionally there may be difficulty obtaining an adequate tissue specimen by this technique (as it is a blind procedure). In these

There may be a role for other gastrointestinal tract biopsies to demonstrate abnormal histology in the presence of chronic constipation (e.g. neuronal intestinal dysplasia:

Magnetic resonance imaging (MRI) of the spine may be performed in children with constipation if the patient history or physical examination is suggestive of spinal pathology. A recent study looked at the result of MRI-spine scans performed on 88 children with intractable constipation. They found that 9% (8 children) had spinal abnormalities on MRI that required surgery (75% of these were a tethered cord). Of these 8 children, 5 had no abnormal signs on physical examination. (Rosen et al., 2004). This study highlights the importance of a thorough history and physical examination in any child presenting with chronic constipation. In particular, one should assess the lower limb neurological status and sacral area for any abnormalities (skin discolouration, naevi, sinuses, hairy patch, central pit

MRI and MR defecography (dynamic pelvic MRI) have also been used in the assessment of anorectal disorders. They have the advantage of being able to simultaneously image anatomy and motility function and a low dosage of radiation exposure. However, there is a high associated cost and very limited data exists on the role of this investigation in children.

There are some other investigations that may be indicated in assessment for underlying

circumstances, a full thickness surgical biopsy may need to be performed.

qualitative and quantitative abnormalities of the myenteric plexus).

**12. Magnetic Resonance Imaging** 

**13. Miscellaneous Investigations** 

causes in chronic constipation. These include the following:

or bony abnormalities).

with a degree of invasiveness and so may not be tolerated well by some children.

**10. Electromyography** 

**11. The role of biopsy** 

defaecation.

manometry.

Most children with chronic constipation do not require any investigations other than a thorough history and physical examination. In patients with intractable constipation or red flags suggestive of an underlying organic aetiology, specialised testing may be indicated and of use. The choice of investigations should be made with specific consideration to the diagnosis being considered.

### **15. References**


### **The Role of Interstitial Cells of Cajal (ICC) in Gastrointestinal Motility Disorders – What the Gastroenterologist Has to Know**

Christian Breuer *Clinic of General Pediatrics, Department of Pediatric Gastroenterology, University Children's Hospital Hamburg-Eppendorf, Germany* 

### **1. Introduction**

32 Constipation – Causes, Diagnosis and Treatment

Dinning, P.G., Benninga, M.A., Southwell, B.R. & Scott, S.M. (2010). Paediatric and adult

Dinning, P.G. & Di Lorenzo, C. (2011). Colonic dysmotility in constipation. *Best Practice and* 

Hussain, S.Z., & Di Lorenzo, C. (2002). Motility disorders, diagnosis and treatment for the paediatric patient. *Pediatric Clinics of North America,* Vol. 49, No.1, pp. 27-51. Joensson, I.M., Siggaard, C., Rittig, S., Hagstroem, S. & Djurhus, J.C. (2008). Transabdominal

Karaman, A., Ramadan, S., Karaman, I., Gokharman, D., Erdogan, D., Kacar, M., Cavusoglu,

Maqbool, S., Parkman, H.P. & Friedenberg, F.K. (2009). Wireless capsule motility:

Nurko, S. (2005). What's the value of diagnostic tools in defecation disorders? *Journal of* 

Papadopoulou, A., Clayden, G.S., & Booth, I.W. (1994). The clinical value of solid marker

Pensabene, L., Buonomo, C., Fishman, L., Chitkara, D. & Nurko, S. (2010). Lack of utility of

Pensabene, L., Youssef, N.N., Griffiths, J.M., & Di Lorenzo, C. (2003). Colonic manometry in

Rao, S.S.C. and Meduri, K. (2011). What is necessary to diagnose constipation? *Best Practice* 

Reuchlin-Vroklage, L.M., Bierma-Zeinstra, S., Benninga, M.A., & Berger, M.Y. (2005).

review. *Archives of Pediatrics and Adolescent Medicine,* Vol. 159, pp. 671-678. Rosen, R., Buonomo, C., Andrade, R., & Nurko, S. (2004). Incidence of spinal cord lesions in patients with intractable constipation. *Journal of Pediatrics,* Vol. 145, pp. 409-411. Southwell, B.R., Clarke, M.C.C., Sutcliffe, J. & Hutson, J.M. (2009). Colonic transit studies:

scintigraphic methods. *Pediatric Surgery International,* Vol. 25, pp. 559-572.

*Pediatric Gastroenterology and Nutrition,* Vol. 41, pp. S53-55.

*Journal of Gastroenterology,* Vol. 98, No.5, pp. 1052-1057.

*and Research Clinical Gastroenterology,* Vol. 25, pp. 127-140.

use ultrasound? *Journal of Pediatric Surgery,* Vol. 45, No. 9, pp. 1849-1855. Leech, S.C., McHugh, K., & Sullivan, P.B. (1999). Evaluation of a method of assessing faecal

*World Journal of Gastroenterology,* Vol. 16, No. 41, pp. 5162-5172.

*Research Clinical Gastroenterology,* Vol. 25, pp. 89-101.

*Urology,* Vol. 179, No. 5, pp. 1997-2002.

255-258.

pp. 1786-1808.

Vol. 153,pp. 560-564.

No. 2, pp. 155-159.

colonic manometry: A tool to help unravel the pathophysiology of constipation.

ultrasound of rectum as a diagnostic tool in childhood constipation. *Journal of* 

Y., & Kosar, U. (2010). Diagnosis and follow-up in constipated children: should we

loading on plain abdominal radiographs in children. *Pediatric Radiology*, Vol. 29, pp.

Comparison of the Smartpill GI monitoring system with scinitigraphy for measuring whole gut transit. *Digestive Diseases and Sciences,* Vol. 54, pp. 2167-2174. Meunier, P., Marechal, J.M., & Mollard, P. (1978). Accuracy of the manometric diagnosis of Hirschsprung's disease. *Journal of Pediatric Surgery,* Vol. 13, pp. 411-415. Nurko, S.S. (2004). Gastrointestinal manometer. Methodology indications. In Walker, W.A.

et al., (Eds). (2004). *Paediatric Gastrointestinal Disease,* B.C. Decker Inc.: Philadelphia,

transit studies in childhood constipation and soiling. *European Journal of Pediatrics,* 

abdominal x-rays in the evaluation of children with constipation: comparison of different scoring methods. *Journal of Pediatric Gastroenterology and Nutrition,* Vol. 51,

children with defecatory disorders: role in diagnosis and management. *American* 

Diagnostic value of abdominal radiography in constipated children: a systematic

normal values for adults and children with comparison of radiological and

Undisturbed gastrointestinal motility or peristalsis is critical for effective digestion and absorption of our food and its ingredients. Peristaltic waves in the gut are propelled by the circular and longitudinal layers of smooth muscle cells in the different segments of the gastrointestinal tract. The initiation and regulation of peristalsis is a complex process which, secondary to smooth muscle cells and enteric nerves, involves pacemaker cells of mesenchymal origin called interstitial cells of Cajal (ICC).

ICC form a network, which is widely distributed in all layers of the gastrointestinal tract. In recent years, there is growing evidence that ICC serve as electrical pacemakers and generate spontaneous electrical slow waves which constitute the basic electrical rhythm in the gastrointestinal tract. Additionally, they are important for the active propagation of slow waves and mediate neurotransmission between inhibitory and excitatory enteric neurons and smooth muscle cells.

Despite their first description more than 100 years ago, only in recent years their importance for the regulation of smooth muscle activity has been discovered. By now the presence of ICC or ICC-like cells has been demonstrated in most visceral organs which generate spontaneous rhythmic muscle contractions, e.g. the urinary and genital system.

The foremost aim of this chapter will be to inform the reader about the recent insights in the role of ICC for the physiologic course of gastrointestinal motility. A short overview about anatomical morphology, signal transduction, physiology and function will be given.

Until recently only little was known about the relevance of ICC as a pathogenetic factor for specific gastrointestinal motility diseases. By now, loss or dysfunction of ICC networks has been associated with slow transit constipation, idiopathic megacolon, diabetic gastropathy, and other diseases of impaired gastrointestinal motility. This chapter will give a short overview about the recent knowledge and highlight the role of ICC in the pathogenesis of gastrointestinal motility disorders.

### **2. History and morphology of interstitial cells of Cajal and the ICC network**

Long lasting constipation is a common problem for up to 10% of the population in the western world. Especially children and elderly people are affected. The symptom of constipation can be the result of many different anatomical, metabolic or functional disorders. For decades physicians and scientists saw the interaction between the enteric nerve system and the smooth muscle cells of the gut as the central point for regulation of sound peristalsis, facilitating proper segmentation and absorption of food and nutrients. Only during the last two decades it became obvious, that the core unit that controls gastrointestinal motility also includes ICC.

For more than 100 years ICC have been known to the histologists as mesenchymal cells ubiquitously distributed within the tunica muscularis of the bowel. The later Nobel prize laureate Santiago Ramón y Cajal first described the cells that are located *interstitially*  between nerve endings and smooth muscle cells (Cajal, 1893). They form a network, which is found in all layers of the gastrointestinal tract. They represent approximately 5% of cells that make up the tunica muscularis and develop independently of neuronal crest-derived enteric neurons or glia from mesenchymal precursor cells. Although we know almost nothing about the metabolism, differentiation, and regeneration of these cells, a dense, comprehensive network of these spindle-shaped cells can be found in the newborn as well as in elderly people.

The distribution of ICC varies between the different layers and different segments of the gastrointestinal tract. Myenteric ICC (ICC-MY) form dense networks and are closely located to the myenteric plexus between the circular and longitudinal layers of the tunica muscularis. More loosely scattered ICC are found in the deep muscular plexus (ICC-DMP) and even in the submucosa of the stomach and colon. Intramuscular ICC within the circular and longitudinal layers of muscle in the gastrointestinal tract (ICC-IM) are closely associated with nerve varicosities throughout the muscularis propria. The tight contact of ICC with nerve cell varicosities and smooth muscle cells prompted theories they might conduct signal transmission between the gastrointestinal nerve system and smooth muscle cells. Already Ramón y Cajal himself suspected their involvement in transduction of nerve impulses after recognizing the close associations between ICC, enteric neurons, and smooth muscle cells. He used methylene blue stains when he characterized the cells at the beginning of the twentieth century so well, that they still bear his name (Cajal, 1911).

Typical ICC are defined through their spindle-shaped, elongated body with several branches and processes. The nucleus is ovoid and a basal lamina and a thick capsula made of collagen may envelope the cells (Faussone-Pellegrini and Thuneberg, 1999). With the support of modern electron microscopy more ultrastructural details of these cells have been defined and they could now be divided into at least three different types by comparing their intracellular characteristics. These include abundant mitochondria, endoplasmatic reticulum and intermediate filaments, whereas contractile proteins are missing. Frequent gap junctions are seen between the ICC to form the network through the bowel wall (Streutker et al., 2007).

In recent years the search for different specific markers for ICC has resulted in a rapidly increasing number of approaches applicable for light and fluorescence microscopy. The new interest in ICC increased rapidly twenty years ago, when Hitomi Maeda established an

For more than 100 years ICC have been known to the histologists as mesenchymal cells ubiquitously distributed within the tunica muscularis of the bowel. The later Nobel prize laureate Santiago Ramón y Cajal first described the cells that are located *interstitially*  between nerve endings and smooth muscle cells (Cajal, 1893). They form a network, which is found in all layers of the gastrointestinal tract. They represent approximately 5% of cells that make up the tunica muscularis and develop independently of neuronal crest-derived enteric neurons or glia from mesenchymal precursor cells. Although we know almost nothing about the metabolism, differentiation, and regeneration of these cells, a dense, comprehensive network of these spindle-shaped cells can be found in the newborn as well

The distribution of ICC varies between the different layers and different segments of the gastrointestinal tract. Myenteric ICC (ICC-MY) form dense networks and are closely located to the myenteric plexus between the circular and longitudinal layers of the tunica muscularis. More loosely scattered ICC are found in the deep muscular plexus (ICC-DMP) and even in the submucosa of the stomach and colon. Intramuscular ICC within the circular and longitudinal layers of muscle in the gastrointestinal tract (ICC-IM) are closely associated with nerve varicosities throughout the muscularis propria. The tight contact of ICC with nerve cell varicosities and smooth muscle cells prompted theories they might conduct signal transmission between the gastrointestinal nerve system and smooth muscle cells. Already Ramón y Cajal himself suspected their involvement in transduction of nerve impulses after recognizing the close associations between ICC, enteric neurons, and smooth muscle cells. He used methylene blue stains when he characterized the cells at the beginning of the

Typical ICC are defined through their spindle-shaped, elongated body with several branches and processes. The nucleus is ovoid and a basal lamina and a thick capsula made of collagen may envelope the cells (Faussone-Pellegrini and Thuneberg, 1999). With the support of modern electron microscopy more ultrastructural details of these cells have been defined and they could now be divided into at least three different types by comparing their intracellular characteristics. These include abundant mitochondria, endoplasmatic reticulum and intermediate filaments, whereas contractile proteins are missing. Frequent gap junctions are seen between the ICC to form the network through the bowel wall (Streutker et al.,

In recent years the search for different specific markers for ICC has resulted in a rapidly increasing number of approaches applicable for light and fluorescence microscopy. The new interest in ICC increased rapidly twenty years ago, when Hitomi Maeda established an

twentieth century so well, that they still bear his name (Cajal, 1911).

**2. History and morphology of interstitial cells of Cajal and the ICC network**  Long lasting constipation is a common problem for up to 10% of the population in the western world. Especially children and elderly people are affected. The symptom of constipation can be the result of many different anatomical, metabolic or functional disorders. For decades physicians and scientists saw the interaction between the enteric nerve system and the smooth muscle cells of the gut as the central point for regulation of sound peristalsis, facilitating proper segmentation and absorption of food and nutrients. Only during the last two decades it became obvious, that the core unit that controls

gastrointestinal motility also includes ICC.

as in elderly people.

2007).

easy-to-use marker protein for ICC, identifying ICC as Kit-expressing cells using an anti-Kit antibody (Maeda et al., 1992). The protein encoded by *c-kit* is the receptor tyrosin kinase Kit

Fig. 1. Normal morphology of c-Kit stained ICC and PGP-positive myenteric neurons in human ileum. Note the dense network of ICC linked by many branches and processes overlying the myenteric ganglion (staining for the neuronal marker PGP 9.5, red; PH164, The Binding Site, Birmingham, UK; staining for c-Kit, green; PC34, Oncogene, Boston, MA, USA).

Fig. 2. Abnormal morphology of myenteric ICC and enteric neurons in the colonic biopsy of an adolescent with slow transit constipation. Note the reduced density and ramification of the ICC network. Also remarkable are the gaps in the ganglion structure, which are highly uncommon in young patients.

(CD117) which is critical for development and function of ICC. Blockade of c-Kit function resulted in mice lacking ICC in the gastrointestinal wall. With electrophysiological examinations Maeda et al. revealed that the slow wave of the guts peristalsis was missing in the animals affected bowel segments. These findings suggested that ICC and c-Kit play a crucial role in the development of the pacemaker system that is required for the generation of autonomic gut motility. This discovery modified the concept of how gastrointestinal motility is controlled dramatically by suggesting that smooth muscle cells need more than just impulses from enteric nerve cells to generate organized gastrointestinal motility. Meanwhile, it is well established that ICC serve as electrical pacemakers and generate spontaneous electrical slow waves in the gastrointestinal tract (Takaki, 2003; Ward et al., 2004). Slow waves organize gut contractions into phasic contractions that are the basis for peristalsis and segmentation.

### **3. Physiology and function of ICC**

The motility of the gastrointestinal tract drives its contents towards the aboral parts of the gut. Local pendular, non-propulsive mixing and propulsive peristaltic waves are taking part in this process. Still, the control of these movements is poorly understood. The intrinsic enteric nervous system consists of more than 100 million neurons. That is approximately the same amount than can be found in the spinal cord. The enteric nerve system therefore represents a complex integrative system which processes sensoric input and motoric output on a highly sophisticated level. As we know today, the regulation by motor neurotransmission is much more complicated than simple release of transmitter from nerve terminals and binding of receptors on smooth muscle cells.

A central part of the gastrointestinal motility regulation are ICC which are closely connected to smooth muscle cells and enteric neurons by gap junctions. They generate rhythmic pacemaker activity which triggers the slow depolarizing membrane potentials accompanying the contractions in smooth muscle cells. The term "slow waves" was coined because of their low frequency of occurrence and long duration (Mostafa et al., 2010). As recent studies confirm, ICC-MY are the specific pacemaker cells in the gut. Even after blocking the gut's neuronal function completely, recordings from isolated muscle cells show a regular pacemaker pattern generated by ICC. The pacemaker potentials generated by ICC-MY are passively propagated to the smooth muscle cells via gap junctions to generate slow waves (Huang and Xu, 2010). Special ICC subpopulations can transfer pacemaker depolarisation from ICC-MY deep into the distant bundles of circular muscle, orchestrating contractile patterns such as the spreading ring of contraction in peristalsis or the alternating contractions of segmentation (Sanders and Ward, 2007).

Slow wave driven peristalsis varies between the segments of the gastrointestinal tract. Whereas in the stomach a primarily unidirectional peristalsis is present, the colon shows a digestive activity which is much more sensitive to modulation by distension or neuronal input. The exact mechanisms for the generation of pacemaker currents still remain controversial. The activity of a pacemaker channel is required, to initiate the pacemaker current. Many studies have shown that inhibitors of calcium channels like cyclopiazonic acid inhibited slow waves and pacemaker currents in ICC (Ward et al., 2000). Therefore, intracellular calcium seems to play an important role in the pacemaker activities. Meanwhile more and more evidence has been gathered that changes in intracellular calcium levels activate non-selective cation channels and/or calcium-activated chloride channels to

(CD117) which is critical for development and function of ICC. Blockade of c-Kit function resulted in mice lacking ICC in the gastrointestinal wall. With electrophysiological examinations Maeda et al. revealed that the slow wave of the guts peristalsis was missing in the animals affected bowel segments. These findings suggested that ICC and c-Kit play a crucial role in the development of the pacemaker system that is required for the generation of autonomic gut motility. This discovery modified the concept of how gastrointestinal motility is controlled dramatically by suggesting that smooth muscle cells need more than just impulses from enteric nerve cells to generate organized gastrointestinal motility. Meanwhile, it is well established that ICC serve as electrical pacemakers and generate spontaneous electrical slow waves in the gastrointestinal tract (Takaki, 2003; Ward et al., 2004). Slow waves organize gut

contractions into phasic contractions that are the basis for peristalsis and segmentation.

The motility of the gastrointestinal tract drives its contents towards the aboral parts of the gut. Local pendular, non-propulsive mixing and propulsive peristaltic waves are taking part in this process. Still, the control of these movements is poorly understood. The intrinsic enteric nervous system consists of more than 100 million neurons. That is approximately the same amount than can be found in the spinal cord. The enteric nerve system therefore represents a complex integrative system which processes sensoric input and motoric output on a highly sophisticated level. As we know today, the regulation by motor neurotransmission is much more complicated than simple release of transmitter from nerve

A central part of the gastrointestinal motility regulation are ICC which are closely connected to smooth muscle cells and enteric neurons by gap junctions. They generate rhythmic pacemaker activity which triggers the slow depolarizing membrane potentials accompanying the contractions in smooth muscle cells. The term "slow waves" was coined because of their low frequency of occurrence and long duration (Mostafa et al., 2010). As recent studies confirm, ICC-MY are the specific pacemaker cells in the gut. Even after blocking the gut's neuronal function completely, recordings from isolated muscle cells show a regular pacemaker pattern generated by ICC. The pacemaker potentials generated by ICC-MY are passively propagated to the smooth muscle cells via gap junctions to generate slow waves (Huang and Xu, 2010). Special ICC subpopulations can transfer pacemaker depolarisation from ICC-MY deep into the distant bundles of circular muscle, orchestrating contractile patterns such as the spreading ring of contraction in peristalsis or the alternating

Slow wave driven peristalsis varies between the segments of the gastrointestinal tract. Whereas in the stomach a primarily unidirectional peristalsis is present, the colon shows a digestive activity which is much more sensitive to modulation by distension or neuronal input. The exact mechanisms for the generation of pacemaker currents still remain controversial. The activity of a pacemaker channel is required, to initiate the pacemaker current. Many studies have shown that inhibitors of calcium channels like cyclopiazonic acid inhibited slow waves and pacemaker currents in ICC (Ward et al., 2000). Therefore, intracellular calcium seems to play an important role in the pacemaker activities. Meanwhile more and more evidence has been gathered that changes in intracellular calcium levels activate non-selective cation channels and/or calcium-activated chloride channels to

**3. Physiology and function of ICC** 

terminals and binding of receptors on smooth muscle cells.

contractions of segmentation (Sanders and Ward, 2007).

conduct the depolarizing pacemaker currents in ICC (Takaki et al., 2010). The frequency of the generated slow wave determines the contractile frequency of the gut.

Additionally to acting as a mere pacemaker for the guts peristalsis, ICC seem to play an important role in transducing inputs from enteric motor neurons. Ultrastructural studies have found synapse-like membrane densities between ICC-IM and enteric nerve terminals. Accessorily, a variety of receptors for neurotransmitters have been identified in ICC. In murine fundus it was shown that ICC-IM were closely associated with cholinergic neurons (Huang and Xu, 2010). These and other results suggest that ICC-IM mediate neurotransmission and signalling between autonomic nerves and smooth muscle cells in the gut (Takaki et al., 2010). Both of the dominant enteric neural motor inputs, i.e. cholinergic and nitrergic, can influence slow wave frequency through communication with ICC (Ward et al., 2004).

The recent data confirms the complexity of gastrointestinal motility and credits ICC with at least three major regulative functions: 1st generating of spontaneous electrical rhythms of the gut known as slow waves, 2nd creating a propagation pathway for slow waves to adjacent parts of the guts musculature, and 3rd mediating excitatory cholinergic and inhibitory nitrergic neuronal inputs from the enteric nervous system. Finally, some novel studies indicate that ICC may serve as nonneural stretch receptors in gut muscle, affecting both smooth muscle excitability and slow wave frequency (Quigley, 2010). Considering the immense effects of ICC on intestinal motility, it should be no surprise that ICC have been in the focus of attention in various gastrointestinal motility disorders. In fact, decreased ICC numbers and abnormal integrity are meanwhile considered a hallmark in diabetic gastropathy as well as in slow transit constipation (Farrugia, 2008). Alterations in the ICC network are thought to have a dramatic effect on the motility of the gastrointestinal system.

### **4. The role of ICC in gastrointestinal motility disorders**

Many gastrointestinal motility disorders have been associated with abnormal numbers or disorders of ICC so far (Burns, 2007; Farrugia, 2008; Ordog et al., 2009). For the clinical workup it is important to keep in mind that no reference values for ICC numbers or network structure have been published. This is due to the different types of biopsy preparations and stainings in use. Therefore, study results have to be interpreted with great care, and comparisons of results from different laboratories can be misleading. For the visualisation of c-Kit (CD117), a receptor tyrosine kinase expressed by ICC, a variety of antibodies is available, yielding results of different quality. Not until 2009 an optimized protocol for improved ICC detection in gastrointestinal motility disorders was presented (Garrity et al., 2009). Since ICC appear very sensitive to hypoxia, abnormalities noted on pathological examination of specimen may also reflect tissue ischemia prior to fixation (Farrugia, 2008).

Most of the ideas regarding the cause of several gastrointestinal motor disorders are still derived from animal models. Because human biopsy samples are still rarely obtained for ICC staining, most case reports published in the literature are describing only a few cases each. However, meanwhile several papers, using a variety of techniques, describing abnormal ICC networks in gastrointestinal motility disorders, have been published. A pubmed search with the keywords "interstitial cells of Cajal" and "gastrointestinal motility" now yields more than 400 results. Whether the observed changes in ICC morphology are primary, secondary or merely epiphenomic remains still much debated (Gladman and Knowles, 2008). Some authors propose that changes in ICC networks in gastrointestinal diseases are due to inflammatory processes or mechanically induced due to long lasting intestinal obstruction. In a number of human motility disorders with abnormal ICC, however, there is no overt inflammation or dilatation suggesting that this cannot be the only reason for the observed ICC abnormalities (Farrugia, 2008).

### **4.1 Achalasia**

ICC of the intramuscular subtype are found in the muscular layers of the oesophagus and especially in the lower oesophageal sphincter (LES). Ultrastructural damage and loss of ICC-IM in the oesophagus have been reported in achalasia (Faussone-Pellegrini and Cortesini, 1985; Streutker et al., 2007). The disease is characterized by an impaired relaxation of the LES, leading to dilatation of the proximal segments of the oesophagus. Etiologically a loss of inhibitory nerves and progressive degeneration of ganglion cells containing vasoactive intestinal peptide (VIP) and nitric oxide (NO) are suspected to be major causes of LES dysfunction (Negreanu et al., 2008). The pathogenetic role of ICC in achalasia is still much debated. Sanders et al. suggest that loss of ICC in the LES would lead to loss of cholingergic tone and changes in LES tension subsequently (Sanders et al., 2002). Although the close anatomical relationship between ICC and cholinergic neurons is well established in electron microscopy, appropriate studies to determine the functional effect of ICC on the regulation of LES relaxation are still lacking.

### **4.2 Gastroesophageal reflux disease (GERD)**

GERD is one of the most common causes for patients to visit a gastroenterologist. The major mechanism is a transient relaxation of the LES (Kaltenbach et al., 2006). Typical symptoms of heartburn and regurgitation are temporarily encountered by almost 20% of the general adult population. However, no specific histopathological abnormalities of ICC have been found and described so far in humans. Animal studies with ICC lacking W/Wv mice showed a normal swallow induced LES relaxation, contradicting a significant role of ICC in the pathogenesis of reflux disease (Dickens et al., 2001). Secondary changes to the ICC architecture may be induced, when GERD is complicated by severe oesophagitis, oesophageal ulcers or Barret's oesophagus (Negreanu et al., 2008).

### **4.3 Diabetic gastroenteropathy**

Gastroparesis is defined as slow gastric emptying which could not be explained by mechanical obstruction. Up to 30-60% of diabetic patients develop associated symptoms, e.g. dysphagia, heartburn, nausea, abdominal pain, or discomfort. In the long term, gastroparesis may lead to more severe symptoms like nutritional insufficiency, electrolyte imbalance, and impaired glycaemic control (Koch, 1999). The pathomechanisms leading to diabetic gastroparesis are complex and are usually interpreted as a consequence of damage to the autonomic nerve system. Only recently studies addressed the role of ICC loss and dysfunction in the pathophysiology of diabetic gastroenteropathy (Ordog, 2008).

Well characterized animal models have been established for the research of diabetes mellitus type 1. In studies with non-obese diabetic mice (NOD-mice), Ordog et al. showed clearly reduced ICC networks by c-Kit immunofluorescence and electron microscopy in the

Knowles, 2008). Some authors propose that changes in ICC networks in gastrointestinal diseases are due to inflammatory processes or mechanically induced due to long lasting intestinal obstruction. In a number of human motility disorders with abnormal ICC, however, there is no overt inflammation or dilatation suggesting that this cannot be the only

ICC of the intramuscular subtype are found in the muscular layers of the oesophagus and especially in the lower oesophageal sphincter (LES). Ultrastructural damage and loss of ICC-IM in the oesophagus have been reported in achalasia (Faussone-Pellegrini and Cortesini, 1985; Streutker et al., 2007). The disease is characterized by an impaired relaxation of the LES, leading to dilatation of the proximal segments of the oesophagus. Etiologically a loss of inhibitory nerves and progressive degeneration of ganglion cells containing vasoactive intestinal peptide (VIP) and nitric oxide (NO) are suspected to be major causes of LES dysfunction (Negreanu et al., 2008). The pathogenetic role of ICC in achalasia is still much debated. Sanders et al. suggest that loss of ICC in the LES would lead to loss of cholingergic tone and changes in LES tension subsequently (Sanders et al., 2002). Although the close anatomical relationship between ICC and cholinergic neurons is well established in electron microscopy, appropriate studies to determine the functional effect of ICC on the regulation

GERD is one of the most common causes for patients to visit a gastroenterologist. The major mechanism is a transient relaxation of the LES (Kaltenbach et al., 2006). Typical symptoms of heartburn and regurgitation are temporarily encountered by almost 20% of the general adult population. However, no specific histopathological abnormalities of ICC have been found and described so far in humans. Animal studies with ICC lacking W/Wv mice showed a normal swallow induced LES relaxation, contradicting a significant role of ICC in the pathogenesis of reflux disease (Dickens et al., 2001). Secondary changes to the ICC architecture may be induced, when GERD is complicated by severe oesophagitis,

Gastroparesis is defined as slow gastric emptying which could not be explained by mechanical obstruction. Up to 30-60% of diabetic patients develop associated symptoms, e.g. dysphagia, heartburn, nausea, abdominal pain, or discomfort. In the long term, gastroparesis may lead to more severe symptoms like nutritional insufficiency, electrolyte imbalance, and impaired glycaemic control (Koch, 1999). The pathomechanisms leading to diabetic gastroparesis are complex and are usually interpreted as a consequence of damage to the autonomic nerve system. Only recently studies addressed the role of ICC loss and

Well characterized animal models have been established for the research of diabetes mellitus type 1. In studies with non-obese diabetic mice (NOD-mice), Ordog et al. showed clearly reduced ICC networks by c-Kit immunofluorescence and electron microscopy in the

dysfunction in the pathophysiology of diabetic gastroenteropathy (Ordog, 2008).

reason for the observed ICC abnormalities (Farrugia, 2008).

**4.1 Achalasia** 

of LES relaxation are still lacking.

**4.3 Diabetic gastroenteropathy** 

**4.2 Gastroesophageal reflux disease (GERD)** 

oesophageal ulcers or Barret's oesophagus (Negreanu et al., 2008).

gastric corpus and antrum in comparison with controls. Both ICC-IM and ICC-MY were affected. Additionally, myenteric ICC were also reduced in the colon. In humans ICC loss in the stomach has also been well documented. In four of nine patients with diabetic gastroparesis profound loss of ICC was observed in biopsy samples of the gastric wall. In another study the same authors reported that nine of 23 patients with gastroparesis showed complete absence of ICC in their antrum biopsies (Forster et al., 2005).

Whether ICC of the small intestine and colon are also affected in humans with diabetes is controversial. Human data is still sparse and patients often suffer from additional maladies such as colonic cancer, which may lead to misinterpretations of the data. In rodent models, however, changes in ICC morphology could also be observed in the proximal and distal colon. However, slow wave frequencies, velocities and extracellular amplitudes were unchanged in a recent study with streptozotocin treated diabetic rats (Lammers et al., 2011), challenging the hypothesis that ICC reduction is severe enough to effect slow wave propagation in the bowel.

Regarding the stomach, the question is, whether the demonstrated changes in ICC morphology are somehow related to the impairment of gastric function in diabetic gastropathy. Delayed emptying of nutrient liquids and solids is caused primarily by antral hypomotility. Reduced smooth muscle contractions as a result of diabetic myopathy and a reduction of pacing electrical slow waves may contribute to the gastric stasis. The role of ICC in the generation and propagation of gastric electrical slow waves is well-established (Ordog, 2008). Abnormal slow wave activity has been shown in different rodent models for diabetes type 1 and 2 combined with diffuse reduction of ICC (Takano et al., 1998). Diabetic rodents showed signs of gastroparesis as well as gastric dysrhythmias. The electrical abnormalities resemble those typically found in human diabetic patients. Thus, reduction in ICC most likely plays a key role in the pathogenesis of diabetic gastroparesis by contributing to gastric hypomotility and delayed gastric emptying.

### **4.4 Infantile hypertrophic pyloric stenosis**

Pyloric stenosis is a congenital disorder characterized by hypertrophy of the inner muscle ring of the pylorus. Signs of delayed gastric emptying are usually not present at birth. Vomiting often starts around the age of three weeks. The etiology is unknown, but abnormal innervation of the pyloric muscle has been implicated. Some studies showed absence of ICC in the hypertrophic circular muscle layer in infants with hypertrophic pyloric stenosis, along with loss of peptidergic and nitric oxide containing nerves (Vanderwinden and Rumessen, 1999). The authors propose the loss of ICC may contribute to the lack of antropyloric coordination and therefore aggravate vomiting and the proper passage of food through the pylorus. An interesting but still unproven theory is that delayed ICC maturation might be one reason explaining the lack of ICC found in immunohistochemnistry and electron microscopy. However, more data is needed to specify the role of ICC in the pathogenesis of hypertrophic pyloric stenosis.

### **4.5 Slow transit constipation (STC)**

Patients suffering from STC show a normal gut diameter and have a prolonged colonic transit. In the majority of cases STC is of unknown etiology. However, it is now well established that ICC play an important role in the pathophysiology of STC. It is plausible that a loss of pacemaker cells would be associated with decrease in colonic transit. Studies proved that ICC density in the colon of patients was significantly decreased compared with those of normal patients (He et al., 2000; Lyford et al., 2002). Expression of *c-kit* mRNA and c-Kit protein in the colon were also decreased in STC, suggesting an important role of the c-Kit signal pathway in the ICC reduction (Tong et al., 2005). Remarkably, these changes in ICC morphology are often accompanied with loss of enteric neurons (Lee et al., 2005) emphasizing the very close relationship between ICC and intrinsic nerves and glial cells. However, a recent study using an automated cellular imaging system for immunohistochemical detection of c-Kit (CD117) showed no significant depletion of ICC. The authors propose that the mere quantification of ICC numbers in the bowel wall may not provide sufficient information on the functional status, since mediation from cholinergic and nitrergic nerves must also be intact for correct ICC function (Toman et al., 2006). Nevertheless, the observed changes in ICC numbers and integrity in patients with STC suggest an important role of ICC when elucidating reduced gastrointestianal motor activity. This has already led some pathology laboratories to include a stain for c-Kit as part of their routine evaluation of specimens resected from patients with STC (Garrity et al., 2009). Future studies will help to understand the exact physiologic and pathopysiologic nature of ICC in STC.

### **4.6 Chronic intestinal pseudo-obstruction**

The term chronic intestinal pseudo-obstruction is used for a group of disorders showing symptoms of intestinal obstruction in the absence of any anatomical or mechanical lesion. Underlying the disease are pathologic disorders from intestinal neuropathy to intestinal myopathy or both. Absence of ICC has been already suggested to be a causative factor leading to intestinal pseudo-obstruction in adults (Vanderwinden and Rumessen, 1999). Yamataka et al. reported abnormal distribution of myenteric ICC in an infant using immunohistochemistry with antihuman c-Kit serum (Yamataka et al., 1998). Recently, one child with total absence of ICC in the myenteric plexus of the distal ileum and colon was reported (Struijs et al., 2008). Feldstein showed altered networks of ICC in a 14-year-old boy (Feldstein et al., 2003). Additionally, delayed maturation of ICC, with normalisation of ICC numbers in subsequent biopsy specimen, has been reported in cases of neonatal pseudoobstruction (Kenny et al., 1998b).

These findings strongly suggest an important etiologic role for ICC at least in some patients with intestinal pseudo-obstruction. Although many more factors may contribute to manifestation and presentation of the disease, the existent data demonstrates that abnormalities of ICC should be considered early in the diagnostic workup of children with intestinal pseudo-obstruction.

### **4.7 Congenital aganglionic megacolon (Hirschsprung's disease)**

In Hirschsprung's disease the intrinsic enteric nervous system is absent in a segment of the gastrointestinal tract. Mostly found in the distal colon, the aganglionosis may also involve large portions of the entire bowel. Some specimen from the aganglionic region of the colon showed reduced ICC numbers and damaged ICC networks (Wang et al., 2009). Other studies however, point out a high heterogeneity in ICC values within a group of Hirschsprung's patients (Bettolli et al., 2008). Hypothetically, the depletion of ICC in the muscular layer of the gut may contribute to the inability of the smooth muscle to relax. Together with the lack of neurons, a defective initiation of pacemaker currents may also contribute to the motility dysfunction in affected bowel segments. Nevertheless, Hirschsprung's disease remains a heterogenous and multigenetic disease and a routine immunohistochemnistry for ICC seems not helpful in differentiation between the healthy and the aganglionic part of the bowel today. Genetic evidence recently confirmed already the absence of linkage between hereditary forms of Hirschsprung's disease and the region of the ICC-regulating gene *c-kit* (Dow et al., 1994; Mostafa et al., 2010).

### **4.8 Idiopathic megacolon**

40 Constipation – Causes, Diagnosis and Treatment

that a loss of pacemaker cells would be associated with decrease in colonic transit. Studies proved that ICC density in the colon of patients was significantly decreased compared with those of normal patients (He et al., 2000; Lyford et al., 2002). Expression of *c-kit* mRNA and c-Kit protein in the colon were also decreased in STC, suggesting an important role of the c-Kit signal pathway in the ICC reduction (Tong et al., 2005). Remarkably, these changes in ICC morphology are often accompanied with loss of enteric neurons (Lee et al., 2005) emphasizing the very close relationship between ICC and intrinsic nerves and glial cells. However, a recent study using an automated cellular imaging system for immunohistochemical detection of c-Kit (CD117) showed no significant depletion of ICC. The authors propose that the mere quantification of ICC numbers in the bowel wall may not provide sufficient information on the functional status, since mediation from cholinergic and nitrergic nerves must also be intact for correct ICC function (Toman et al., 2006). Nevertheless, the observed changes in ICC numbers and integrity in patients with STC suggest an important role of ICC when elucidating reduced gastrointestianal motor activity. This has already led some pathology laboratories to include a stain for c-Kit as part of their routine evaluation of specimens resected from patients with STC (Garrity et al., 2009). Future studies will help to understand the exact physiologic and pathopysiologic nature of

The term chronic intestinal pseudo-obstruction is used for a group of disorders showing symptoms of intestinal obstruction in the absence of any anatomical or mechanical lesion. Underlying the disease are pathologic disorders from intestinal neuropathy to intestinal myopathy or both. Absence of ICC has been already suggested to be a causative factor leading to intestinal pseudo-obstruction in adults (Vanderwinden and Rumessen, 1999). Yamataka et al. reported abnormal distribution of myenteric ICC in an infant using immunohistochemistry with antihuman c-Kit serum (Yamataka et al., 1998). Recently, one child with total absence of ICC in the myenteric plexus of the distal ileum and colon was reported (Struijs et al., 2008). Feldstein showed altered networks of ICC in a 14-year-old boy (Feldstein et al., 2003). Additionally, delayed maturation of ICC, with normalisation of ICC numbers in subsequent biopsy specimen, has been reported in cases of neonatal pseudo-

These findings strongly suggest an important etiologic role for ICC at least in some patients with intestinal pseudo-obstruction. Although many more factors may contribute to manifestation and presentation of the disease, the existent data demonstrates that abnormalities of ICC should be considered early in the diagnostic workup of children with

In Hirschsprung's disease the intrinsic enteric nervous system is absent in a segment of the gastrointestinal tract. Mostly found in the distal colon, the aganglionosis may also involve large portions of the entire bowel. Some specimen from the aganglionic region of the colon showed reduced ICC numbers and damaged ICC networks (Wang et al., 2009). Other studies however, point out a high heterogeneity in ICC values within a group of Hirschsprung's patients (Bettolli et al., 2008). Hypothetically, the depletion of ICC in the

**4.7 Congenital aganglionic megacolon (Hirschsprung's disease)** 

ICC in STC.

**4.6 Chronic intestinal pseudo-obstruction** 

obstruction (Kenny et al., 1998b).

intestinal pseudo-obstruction.

In contrast to the congenital megacolon known as Hirschsprung's disease, patients with acquired megacolon show no aganglionic bowel segments and the enteric innervation seems to be intact. Thus, it had been proposed that colonic dysmotility in these patients might as well result from alterations of ICC. Accordingly, some studies of patients with idiopathic megabowel showed decreased ICC density (Lee et al., 2005; Wedel et al., 2002). By contrast, another study of sixty-three patients with megacolon showed no consistent alterations in colonic ICC histology (Meier-Ruge et al., 2006). The results suggest once again that ICC might play an important etiologic role, however more systematic studies are needed to determine the detailed pathomechanisms.

### **4.9 Children with anorectal malformations**

Anorectal malformations comprise a wide spectrum of diseases, which involve the distal anus and rectum as well as the urinary and genital tracts. Defects range from minor anal anomalies to very complex cloacal malformations, which are often associated with other anomalies (Levitt and Pena, 2007). The etiology of such malformations remains unclear and is likely multifactorial. However, in recent years a dramatic progress in operation techniques has improved prognosis significantly.

Constipation, eventually leading to megarectum and functional outlet obstruction, is a common postsurgical problem faced by more than a half of all patients with anorectal malformations. Although in some of these patients aganglionosis or neuronal intestinal dysplasia have been reported, no plausible theory could explain colonic hypomotility satisfactorily so far. Often these symptoms have been attributed to associated abnormalities of the sacral roots or to inherent abnormalities of the myenteric plexus.

Using monoclonal mouse antibody against c-Kit, Kenny et al. reported marked abnormalities in density and distribution of c-Kit-positive ICC in the sigmoid colon in 7 of 12 patients with high or intermediate anorectal malformations (Kenny et al., 1998a). Since no electron microscopy was applied, the authors state that it is uncertain, if the loss of c-Kit immunoreactivity was caused by phenotypic loss of c-Kit antigen, or by complete absence of ICC. The latter would advance speculations that genes involved in gut segmentation and hindgut differentiation are also essential for ICC development. Supporting this, a lower density of ICC in the terminal intestine was recently observed in rats with ethylenethioureainduced anorectal malformations (Macedo et al., 2008). Although not enough sufficient data is available today, congenital defects in interstitial pacemaker cells may, additionally to other factors, contribute to the colonic hypomobility in patients with anorectal malformations.

### **4.10 Patients with mutations of** *c-kit* **and constipation**

Signals through the c-Kit receptor tyrosine kinase are essential for development and differentiation of erythrocytes, melanocytes, germ cells, mast cells, and ICC. Gain-offunction mutations of *c-kit* result in the development of mast cell and germ cell tumors, and of ICC tumors called gastrointestinal stromal tumors (GIST), respectively (Kitamura and Hirotab, 2004). In mice the W locus was demonstrated to encode c-Kit, and meanwhile various types of mutants have been reported. Animal models with loss-of-function mutations in the *c-kit* gene compromise the regular development of ICC in the gut (Alberti et al., 2007; Maeda et al., 1992; Sanders and Ward, 2007). In humans however, no homozygote loss-of-function mutations have been reported so far.

Recently one juvenile patient was described whose biopsy specimen showed only few ICC in the ileum and complete absence of ICC in the colon (Breuer et al., 2010). The mutational analysis of Kit in this patient revealed multiple genetic alterations at the level of mRNA which potentially could result in a loss of function of the Kit protein. According to this, it was suggested that the genetic alterations of *c-kit* might lead to alterations in ICC architecture and function.

By now animal studies have already shown that point mutations in the proto-oncogene *c-kit* correlate with abnormal intestinal contractions *in vitro* (Isozaki et al., 1995). Kit mutations might therefore explain cases of patients with megacolon or small transit constipation who show histopathological defects or depletion of ICC. The Wsh/Wsh c-Kit mutant illustrates the complexity of Kit-regulated ICC differentiation. Although leading to a general absence of ICC in the intestine due to an inversion mutation upstream the promoter region, a subpopulation of special ICC in the deep muscular plexuses (ICC-DMP) developed normally in mutant mice. These findings suggest that ICC-DMP may develop and differentiate without c-Kit expression (Iino et al., 2009).

### **5. Summary**

Constipation and fecal impaction are frequent and distressing complaints in gastroenterology. In most cases a sufficient treatment including changes in lifestyle, activity, and food, with the additional use of laxatives is possible. However, the treatment of severe forms of constipation may constitute a difficult task.

In recent years the role of ICC in gastrointestinal motility is increasingly recognized. Throughout the whole gastrointestinal tract ICC-MY and ICC-IM coordinate smooth muscle activity and guarantee the physiologic course of peristalsis. Whereas ICC-MY act as pacemaker cells to generate slow waves driven by changes of voltage dependent calcium channels, ICC-IM mediate neurotransmission between enteric neurons and smooth muscle cells. Meanwhile lots of cases with histological alterations in ICC morphology have been presented in patients with different types of constipation. However, it occasionally remains unclear, whether morphological alterations of ICC are based on congenital developmental anomalies or whether they are a consequence of long term constipation with secondary damage of the guts neuroarchitecture. Nevertheless, the new insights in ICC physiology and function present a new aspect for gastroenterologists to focus on, when dealing with patients suffering from severe forms of constipation. Clinicians should consider involvement of ICC early in the diagnostic process of motility disorders. Further investigations may lead to the routine staining and evaluation of ICC-morphology in intestinal biopsy specimen.

Although the knowledge of the role of ICC in gastrointestinal disorders is increasing rapidly, no major progress has been achieved in treatment so far. The Kit inhibitor Imatinib mesylate has been shown to be effective in Kit expressing tumors (GISTs), but no drugs improving loss of c-Kit function are available today. Eventually new medications modulating gastrointestinal peristalsis may be provided in the future. Replacement of defective pacemaker cells however, will be a prospective promise of genetic therapy at best.

### **6. References**

42 Constipation – Causes, Diagnosis and Treatment

Signals through the c-Kit receptor tyrosine kinase are essential for development and differentiation of erythrocytes, melanocytes, germ cells, mast cells, and ICC. Gain-offunction mutations of *c-kit* result in the development of mast cell and germ cell tumors, and of ICC tumors called gastrointestinal stromal tumors (GIST), respectively (Kitamura and Hirotab, 2004). In mice the W locus was demonstrated to encode c-Kit, and meanwhile various types of mutants have been reported. Animal models with loss-of-function mutations in the *c-kit* gene compromise the regular development of ICC in the gut (Alberti et al., 2007; Maeda et al., 1992; Sanders and Ward, 2007). In humans however, no

Recently one juvenile patient was described whose biopsy specimen showed only few ICC in the ileum and complete absence of ICC in the colon (Breuer et al., 2010). The mutational analysis of Kit in this patient revealed multiple genetic alterations at the level of mRNA which potentially could result in a loss of function of the Kit protein. According to this, it was suggested that the genetic alterations of *c-kit* might lead to alterations in ICC

By now animal studies have already shown that point mutations in the proto-oncogene *c-kit* correlate with abnormal intestinal contractions *in vitro* (Isozaki et al., 1995). Kit mutations might therefore explain cases of patients with megacolon or small transit constipation who show histopathological defects or depletion of ICC. The Wsh/Wsh c-Kit mutant illustrates the complexity of Kit-regulated ICC differentiation. Although leading to a general absence of ICC in the intestine due to an inversion mutation upstream the promoter region, a subpopulation of special ICC in the deep muscular plexuses (ICC-DMP) developed normally in mutant mice. These findings suggest that ICC-DMP may develop and

Constipation and fecal impaction are frequent and distressing complaints in gastroenterology. In most cases a sufficient treatment including changes in lifestyle, activity, and food, with the additional use of laxatives is possible. However, the treatment of severe

In recent years the role of ICC in gastrointestinal motility is increasingly recognized. Throughout the whole gastrointestinal tract ICC-MY and ICC-IM coordinate smooth muscle activity and guarantee the physiologic course of peristalsis. Whereas ICC-MY act as pacemaker cells to generate slow waves driven by changes of voltage dependent calcium channels, ICC-IM mediate neurotransmission between enteric neurons and smooth muscle cells. Meanwhile lots of cases with histological alterations in ICC morphology have been presented in patients with different types of constipation. However, it occasionally remains unclear, whether morphological alterations of ICC are based on congenital developmental anomalies or whether they are a consequence of long term constipation with secondary damage of the guts neuroarchitecture. Nevertheless, the new insights in ICC physiology and function present a new aspect for gastroenterologists to focus on, when dealing with patients suffering from severe forms of constipation. Clinicians should consider involvement of ICC early in the diagnostic process of motility disorders. Further

**4.10 Patients with mutations of** *c-kit* **and constipation** 

homozygote loss-of-function mutations have been reported so far.

differentiate without c-Kit expression (Iino et al., 2009).

forms of constipation may constitute a difficult task.

architecture and function.

**5. Summary** 


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## **Skipping Breakfast is Associated with Constipation in Post-Adolescent Female College Students in Japan**

Tomoko Fujiwara *Faculty of Home Economics, Ashiya College, Ashiya, Japan* 

### **1. Introduction**

46 Constipation – Causes, Diagnosis and Treatment

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neural control of gastrointestinal smooth muscles. Neurogastroenterol Motil *16* 

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Intake of food is one of the most effective stimulations that induce bowel movement. Food intake stimulates bowel peristalsis mainly through automatic nerve system (Nobel et al., 2009). On the other hand, it is widely accepted that physiological and/or psychological stresses can induce constipation in women by suppressing the function of parasympathetic nerve networks (Whitehead, 1996).

In general, the dominance of the parasympathetic nerve system while sleeping promotes digestive and absorptive function. In this regard, the time dinner is eaten may be a factor that influences the conditions of bowel movement the following day. In addition, intake of breakfast is an important event that gives an opportunity to empty the bowels in the morning when the work day usually starts (Cummings JH). Accordingly, it is speculated that late intake of dinner or skipping breakfast can disrupt the rhythms of bowel movement, inducing various problems such as constipation.

To support the above speculation, Kunimoto *et al*. reported that skipping breakfast is strongly related to constipation in Japanese working women and signs of this relationship have already appeared in adolescents (Kunimoto *et al*., 1998). In accordance with this study, we also observed the positive relationship between breakfast skipping and constipation in Japanese young female students (Fujiwara and Nakata, 2010).

In this study, we re-evaluated the relationship between skipping breakfast and bowel movement by conducting an 11-year questionnaire survey (from 2000 to 2010) of 1,877 female college students aged between 18 and 20 years old. We further examined the relationship between dinner time and bowel movement by conducting a single year questionnaire survey in 2010.

### **2. Methods**

### **2.1 Respondents to a questionnaire**

The subjects were yong Japanese women aged from 18 to 20 years old who studied at the Faculty of Home Economics of Ashiya College and Kyoto Bunkyo Junior College. The study protocol was approved by the Committee on Food Culture at Ashiya College. We sent questionnaires to all students who belonged to the Faculty of Home Economics and Child Education between 2000 and 2010. Information regarding the aim of this study was sent with the questionnaire, and consent was obtained from all participants. The total number of the participants in the sequential studies was 1898 and we obtained responses that were suitable for statistical analysis from 1,877 students in the sequential study.

### **2.2 Questionnaire items**

### **2.2.1 Skipping breakfast**

All study participants completed a food-frequency questionnaire about breakfast (food intake until 9:00 am) and were divided into three groups as follows: Group I, having breakfast every morning; Group II, having breakfast one to six times a week; and Group III, having breakfast less than once a week.

### **2.2.2 Body mass index (BMI) assessment**

Information on body mass (kilograms) and height (meters) of all participants were obtained from a physical examination organized by the Health Center at Ashiya College and Kyoto Bunkyo Junior College. BMI was calculated using the formula: body weight in kilograms divided by height in meters squared.

### **2.2.3 Bowel movement**

The frequency of bowel movement was classified into Grade 1 (no more than once a week), Grade 2 (2-6 times a week), and Grade 3 (every day).

### **2.2.4 Time of dinner intake**

Participants in 2010 were divided into three groups according to the time of dinner as follows: Group A, having dinner before 19:00; Group B, having dinner between 19:00 and 21:00; Group C, having dinner after 21:00.

### **2.3 Statistical analysis**

The data are shown as mean ± standard deviation (SD). Differences in the bowel movement among Groups I-III and A-C were analyzed by the Kruskal-Wallis test, followed by the Mann-Whitney test for multiple comparisons. The relationship between BMI and skipping breakfast was analyzed by one-way analysis of variance, followed by Scheffe's F test for multiple comparisons. *P*-values less than 0.05 were considered significant.

### **3. Results**

### **3.1 Changes over time in the proportions of the population showing various breakfast habits**

Among the participants, 1877 students were classified in Groups I, II and III. Annual population rates for breakfast habits between 2000 and 2010 are shown in Figure 1. Population of breakfast skipping has been within 5-22% throughout the study.

protocol was approved by the Committee on Food Culture at Ashiya College. We sent questionnaires to all students who belonged to the Faculty of Home Economics and Child Education between 2000 and 2010. Information regarding the aim of this study was sent with the questionnaire, and consent was obtained from all participants. The total number of the participants in the sequential studies was 1898 and we obtained responses that were

All study participants completed a food-frequency questionnaire about breakfast (food intake until 9:00 am) and were divided into three groups as follows: Group I, having breakfast every morning; Group II, having breakfast one to six times a week; and Group III,

Information on body mass (kilograms) and height (meters) of all participants were obtained from a physical examination organized by the Health Center at Ashiya College and Kyoto Bunkyo Junior College. BMI was calculated using the formula: body weight in kilograms

The frequency of bowel movement was classified into Grade 1 (no more than once a week),

Participants in 2010 were divided into three groups according to the time of dinner as follows: Group A, having dinner before 19:00; Group B, having dinner between 19:00 and

The data are shown as mean ± standard deviation (SD). Differences in the bowel movement among Groups I-III and A-C were analyzed by the Kruskal-Wallis test, followed by the Mann-Whitney test for multiple comparisons. The relationship between BMI and skipping breakfast was analyzed by one-way analysis of variance, followed by Scheffe's F test for

**3.1 Changes over time in the proportions of the population showing various breakfast** 

Among the participants, 1877 students were classified in Groups I, II and III. Annual population rates for breakfast habits between 2000 and 2010 are shown in Figure 1.

multiple comparisons. *P*-values less than 0.05 were considered significant.

Population of breakfast skipping has been within 5-22% throughout the study.

suitable for statistical analysis from 1,877 students in the sequential study.

**2.2 Questionnaire items 2.2.1 Skipping breakfast** 

having breakfast less than once a week.

divided by height in meters squared.

21:00; Group C, having dinner after 21:00.

**2.2.3 Bowel movement** 

**2.2.4 Time of dinner intake** 

**2.3 Statistical analysis** 

**3. Results** 

**habits** 

**2.2.2 Body mass index (BMI) assessment** 

Grade 2 (2-6 times a week), and Grade 3 (every day).

### **3.2 Changes over time in bowel movement scores**

There was a tendency for bowel movement scores in Group I to be higher than those in the other groups throughout the study (Figure 1).

Fig. 1. Changes in population rates and bowel movement scores in Groups I, II and III throughout an 11-year surveillance period from 2000 to 2010. Population of breakfast skipping has been within 5-22% and bowel movement scores in Group I are higher than those in the other groups throughout the study.

#### **3.3 Relationship between breakfast habits and bowel movement scores**

The bowel movement score was significantly lower in Group III than in Group I and II (Figure 2).

Fig. 2. Relationship between skipping breakfast and bowel movement scores. The bowel movement score was significantly lower in Group III than in Group I and Group II, suggesting that skipping breakfast induced constipation in young students.

### **3.4 The differences in BMI scores**

50 Constipation – Causes, Diagnosis and Treatment

The bowel movement score was significantly lower in Group III than in Group I and II

Fig. 2. Relationship between skipping breakfast and bowel movement scores. The bowel movement score was significantly lower in Group III than in Group I and Group II,

suggesting that skipping breakfast induced constipation in young students.

**3.3 Relationship between breakfast habits and bowel movement scores** 

(Figure 2).

As shown in Figure 3, there were no significant differences in BMI scores among Group I, II and III. There were no significant changes in BMI scores throughout the observation periods.

Fig. 3. Relationship between skipping breakfast and BMI. There were no significant changes in BMI scores among three groups.

### **3.5 Relationship between dinner time and bowel movement scores**

Bowel movement scores in Group A were significantly higher than those of the other two groups (Figure 4).

Fig. 4. Relationship between dinner time and bowel movement scores. Bowel movement scores in Group A were significantly higher than those of the other two groups.

### **4. Discussion**

For more than a decade, we have been studying the relationship between food habits and quality of life (QOL) in young Japanese women by analyzing the responses to a questionnaire completed by Ashiya College and Kyoto Bunkyo Junior College students. Since the educational and social environment of these populations remained stable throughout this longitudinal survey, we think that the results obtained from these data convincingly represent annual changes in the status of young Japanese women and provide important information.

We previously reported that skipping breakfast is significantly related with poor physical conditions in Japanese female young students (Fujiwara and Nakata, 2010). The present study showed that small population of young students habitually skipped breakfast. Fortunately, this percentage seems to have decreased in recent years (Figure 1). However, it should be noted that accumulating evidence has been suggesting that habits of food intake considerably affects QOL in women. To support this concern, this study clearly showed that students who skip breakfast have a significantly lower frequency of bowel movement compared with that in young women who eat breakfast (Figure 2). This suggests that skipping breakfast induces constipation in young female students.

Bowel movement scores in Group A were significantly higher than those of the other two

Fig. 4. Relationship between dinner time and bowel movement scores. Bowel movement

For more than a decade, we have been studying the relationship between food habits and quality of life (QOL) in young Japanese women by analyzing the responses to a questionnaire completed by Ashiya College and Kyoto Bunkyo Junior College students. Since the educational and social environment of these populations remained stable throughout this longitudinal survey, we think that the results obtained from these data convincingly represent annual changes in the status of young Japanese women and provide

We previously reported that skipping breakfast is significantly related with poor physical conditions in Japanese female young students (Fujiwara and Nakata, 2010). The present study showed that small population of young students habitually skipped breakfast. Fortunately, this percentage seems to have decreased in recent years (Figure 1). However, it should be noted that accumulating evidence has been suggesting that habits of food intake considerably affects QOL in women. To support this concern, this study clearly showed that students who skip breakfast have a significantly lower frequency of bowel movement compared with that in young women who eat breakfast (Figure 2). This suggests that

scores in Group A were significantly higher than those of the other two groups.

skipping breakfast induces constipation in young female students.

**3.5 Relationship between dinner time and bowel movement scores** 

groups (Figure 4).

**4. Discussion** 

important information.

In general, food intake especially just after waking up effectively stimulates stomach and induces bowel movement via the parasympathetic nerve pathway. Therefore, it is reasonably speculated that skipping breakfast decreased stimulation to digestive organs in the morning, causing reduction and irregularity of bowel movement. Abnormality in food intake can induce some degree of nutritional defect. Since social activity is relatively high in the morning, skipping breakfast may contribute to a nutritional defect that can affect QOL. However, this study showed that there was no significant difference in BMI among 3 groups (Figure 3). These findings suggest that breakfast skipping had little effects on the total supply of energy for young students and suggested that the positive relationship between breakfast skipping and constipation is due to the disarrangement of the rhythms of automatic nerve systems.

Interestingly, the preliminary study suggested a new proposal that early intake of dinner can improve bowel movement in young female students. Although we cannot exclude the effects of factors accompanying the early intake of dinner, these data notably demonstrated that intake of dinner before 19:00, but not between 19:00 and 21:00, had significant effects on improvement of bowel movement. Considering that intake of dinner between 19:00 and 21:00 has become a common life style practice in modern civilized countries, it is suggested that an intrinsic ideal dietary rhythm for bowel movement in humans differs from our dietary habits.

From the sequential survey conducted in this study, we also found that skipping breakfast is associated with female reproductive disorders such as dysmenorrhea (Fujiwara T, 2003) and proposed that impairment of reproductive function by skipping breakfast may become a trigger for the subsequent onset of gynecologic diseases such as endometriosis in the future (Fujiwara T, 2007). Thus, although the precise mechanisms are still unknown, it is speculated that physiological or pathological conditions of the pelvic organs can be influenced by dietary habits (Fujiwara et al., 2009). Consequently, considering the possibility that constipation influences the environment of pelvic cavity, the relationship between constipation and female genital organic disorders should be examined in the future.

### **5. Conclusion**

In conclusion, by conducting a questionnaire survey, this study suggested that early intake of dinner promoted, while skipping breakfast reduced bowel movement in young Japanese female students. These findings support the current concept that dietary habits regulate bowel functions. Since constipation can cause psychological and/or organic disorders, this issue should be re-evaluated from the perspective of dietary rhythm.

### **6. References**

Cummings, J.H. (1984) Constipation, dietary fibre and the control of large bowel function. *Postgraduate Medical Journal*, 60, 811-819.

Fujiwara, T. (2003). Skipping breakfast is associated with dysmenorrhea in young women in Japan. *International Journal of Food Science and Nutrition*, 54, 505-509.


## **Irritable Bowel Syndrome and Constipation**

### Brian C. Dobson

*Performance Edge Systems New Zealand* 

### **1. Introduction**

54 Constipation – Causes, Diagnosis and Treatment

Fujiwara, T. (2007). Diet during adolescence is a trigger for subsequent development of

Fujiwara, T., Sato, N., Awaji, H., Sakamoto, H., & Nakata, R. (2009). Skipping Breakfast

Fujiwara, T. & Nakata R. (2010) Skipping breakfast is associated with reproductive dysfunction in post-adolescent female college students. *Appetite,* 55, 714-717. Kunimoto, M., Nishi, M., & Sasaki K. (1998) The relation between irregular bowel movement and the lifestyle of working women. *Hepatogastroenterology*, 45, 956-960*.*  Noble, E.J., Harris, R., Hosie, K.B., Thomas, S. & Lewis, S.J. (2009) Gum chewing reduces

Whitehead, W.E. (1996) Psychosocial aspects of functional gastrointestinal disorders.

*Journal of Food Science and Nutrition,* 26, 1-9.

*Gastroenterology Clinics of North America*, 25, 21-34.

58, 437-444.

*Surgery*, 7, 100-105.

dysmenorrhea in young women. *International Journal of Food Science and Nutrition,*

Adversely Affects Menstrual Disorders in Young College Students. *International* 

postoperative ileus? A systematic review and meta-analysis. *International Journal of* 

A hypothetical model of the digestive system that can create the symptoms of Irritable Bowel Syndrome (IBS) was originally published as (Dobson, 2008). This chapter presents the model and includes additional research. The model accounts for all types of IBS.

A mechanism that creates **constipation**, improved diagnostic criteria, suggestions for testing the model, treatment options, diagrams showing how the autonomic nervous system creates IBS symptoms, and photomicrographs of the insoluble food fibres triggering IBS, are included.

The data necessary to write this chapter was collected over four decades. Initially the aim of the research was to treat a member of the author's family who has severe IBS-D, and successful treatment programs have been developed. In addition the observed symptoms of all types of IBS, have suggested the hypothesis on which this chapter is based.

### **2. A worldwide digestive illness**

IBS is one of the most common maladies that a GP encounters. The symptoms of IBS range from mild and intermittent, to severe, continuous and incapacitating. Rates of occurrence have been measured at up to 25% in some countries. The economic burden is tens of billions of dollars annually for the USA alone (Schwetz & Chang, 2004) (Drossman, 2007).

GPs diagnose IBS by eliminating other digestive disorders. The symptoms demonstrate that something is wrong but they can find no visible damage. The GP has few treatment options available and they are often ineffective. The patient goes away and tries to cope. Their days can be miserable. They may suffer from **constipation**, bloating, cramping, diarrhoea, all four, or even none of these and instead, a host of other ailments. They may be unable to work, afraid to eat, and suffer from weight loss & malnutrition. They may have herb & fibre supplements, laxatives, and/or anti-diarrhoea medicines at hand. The author has also noted secondary symptoms such as depression, headache, hallucinations, guts ache, lack of energy, weight loss, skin infections, back pain, aching limbs, athlete's foot, ingrown nails, and other minor problems caused by malnutrition.

### **2.1 Types of IBS**

These three types are widely recognized (Drossman 2007): IBS-C (**constipatio**n predominant), IBS-D (diarrhoea predominant), and IBS-A or IBS-M (alternating or mixed, **constipation** & diarrhoea).

These descriptions contain the symptoms as observed by the author…


### **3. The hypothesis**

Digestion in the small intestine is a batch process with three sequential sections corresponding to the natural divisions of the intestine. These are the duodenum, the jejunum, and the ileum. It is governed by a brain controller divided into four subcontrollers, each of which has a unique neurotransmitter. Control faults in this process cause the disorder irritable bowel syndrome.

This hypothesis has been created by the author in order to explain the symptoms of IBS that he has observed over a period of decades. It accurately creates all types of IBS when faults occur in its control mechanisms.

### **3.1 Transport controllers**

There are two transport control systems for the process…


### **3.2 Chemical controllers**

Two systems control addition of digestive chemicals to the duodenum…

1. IBS-C… the primary symptom is **constipation**. Bloating may be hard to detect but is always present. It begins in the morning when breakfast is eaten and then may disappear overnight. Bowel movements are hard to pass, and diarrhoea never occurs. Borborygmi (gurgling), cramping, and difficulty with fat digestion may be present. 2. IBS-D… the primary symptom is diarrhoea. This usually occurs on arising as the 'morning rush', but it can also happen at other times. When **constipation** is a symptom, bloating is never present. Borborygmi and irritation around the anus are always

3. IBS-A or IBS-M… bloating, **constipation** and diarrhoea that alternate irregularly are the primary symptoms. Borborygmi, irritation around the anus, cramping, and difficulty

Digestion in the small intestine is a batch process with three sequential sections corresponding to the natural divisions of the intestine. These are the duodenum, the jejunum, and the ileum. It is governed by a brain controller divided into four subcontrollers, each of which has a unique neurotransmitter. Control faults in this process cause

This hypothesis has been created by the author in order to explain the symptoms of IBS that he has observed over a period of decades. It accurately creates all types of IBS when faults

1. The primary control system is a brain controller that is part of the autonomic nervous system. It is divided into four sub-controllers. The duodenum, the jejunum & the ileum each have a dedicated transport sub-controller. These three sub-controllers produce output only when input is received. They obtain input from sensors in the walls of the intestine that detect food soup. Output regulates transport and mixing in the small intestine. Correct control happens regardless of the variable input caused by different foods. The food soup is moved backwards and forwards so that chemicals can be mixed in, and the rate of absorption of nutrients & chemicals controlled. It is then transferred

2. A secondary control system called the MMC is applied when primary controller outputs are absent. This is a reflex action of the enteric nervous system. It is normally only active when the intestine has no food in it. When food is present, and the primary controller is defective, the transport speed set by the secondary controller is dependent on the type of foods eaten and the state of the autonomic nervous system. There is no control of mixing or timing, and movement is in the forward direction only. When the

to the next section at the correct time, and at the correct speed (slow).

Two systems control addition of digestive chemicals to the duodenum…

These descriptions contain the symptoms as observed by the author…

present. Cramping and difficulty with fat digestion may be present.

with fat digestion may be present.

the disorder irritable bowel syndrome.

There are two transport control systems for the process…

occur in its control mechanisms.

speed is too fast, IBS occurs.

**3.2 Chemical controllers** 

**3.1 Transport controllers** 

**3. The hypothesis** 


### **3.3 Primary control faults**

The following defects may occur…


### **3.4 IBS-B – Bile deficient IBS**

When the neurotransmitter in the primary chemical controller is missing or deficient, insufficient lipases and bile salts are added to the food soup. Undigested fats impair nutrient uptake in the jejunum, and the reabsorbtion of chemicals in the ileum. Indigestion is followed by fast, loose, grey bowel movements containing fat (steatorrhea). The absence of the brown bile pigment stercobilin causes the grey colour, and when fat is present in the colon, the enteric nervous system automatically evacuates it. IBS-B may occur alone but often it accompanies one of the other three types of IBS. When it does, the symptoms of the other types become severe.

### **3.5 Constipation – Creation of the IBS barrier**

The IBS Barrier is created when food soup is present in the small intestine, and a section under the control of the secondary transport controller precedes a section under the control of the primary transport controller. When the primary controller detects the too fast movement of food soup, it constricts the intestine to stop the flow. It will not allow food soup to travel too fast. The Barrier causes the IBS symptoms of bloating and **constipation**.

The Barrier is created by parts of the autonomic nervous system. Variation in the level of activity in this system causes Barrier strength to vary. It is strong on arising when adrenal hormones are released to start the metabolism. The symptoms of the Barrier start when breakfast is eaten. When stress releases more adrenal hormones during the day it again increases in strength. It will relax overnight if adrenal hormones and the autonomic nervous system return to a low level.

### **3.5.1 IBS-C caused by a neurotransmitter deficiency**

There are six forms;



Legend: X = defective and O = functioning

Table 1. Summary of the six forms of IBS-C

Diagram 1. Schematic showing how the model creates IBS-C form (a)

The Barrier is created by parts of the autonomic nervous system. Variation in the level of activity in this system causes Barrier strength to vary. It is strong on arising when adrenal hormones are released to start the metabolism. The symptoms of the Barrier start when breakfast is eaten. When stress releases more adrenal hormones during the day it again increases in strength. It will relax overnight if adrenal hormones and the autonomic nervous

a. The duodenum controller output is deficient or missing. This causes a Barrier to form at the start of the jejunum. When a breakfast containing cereal is eaten, immediate, severe bloating occurs. Backpressure in the duodenum keeps the valve from the gall bladder and pancreas closed, so that insufficient chemicals are added to the food soup (see Diagram 1).

c. The jejunum controller output is deficient or missing. This causes a Barrier to form at the start of the ileum. When a breakfast containing cereal is eaten, borborygmi occurs followed by hard to detect, slight to moderate bloating. Onset of these symptoms is

> Immediate severe bloating that disappears overnight. Cramping possible. **Constipation**.

> Immediate severe bloating that disappears overnight. Cramping & borborygmi possible. **Constipation**. Steatorrhea. Severe symptoms.

Delayed borborygmi and delayed hard to detect, mild, bloating that disappears overnight. Cramping possible. **Constipation.**

Delayed borborygmi and delayed hard to detect, mild, bloating that disappears overnight. Cramping possible. **Constipation.**

Immediate borborygmi and immediate hard to detect, mild, bloating that disappears overnight. Cramping possible. **Constipation.**

Immediate borborygmi and immediate hard to detect, mild, bloating that disappears overnight. Cramping possible. **Constipation.**

Steatorrhea. Severe symptoms.

Steatorrhea. Severe symptoms.

Steatorrhea. No borborygmi.
