**2. Epidemiology of gastrointestinal symptoms and endometriosis**

It is becoming apparent that although anatomically separate, gastrointestinal symptoms do overlap with pelvic endometriosis. Endometriosis is the occurrence of endometrial tissue outside the uterus. Endometriotic deposits are mainly found on the ovaries, utero-sacral ligaments and pelvic peritoneum. Endometriosis affects one fourth of young women under the age of 30 years with an overall incidence of 7% to 10 % of women. Subfertility has been noted in 20-50% of women found to have endometriosis while more than 80% of women

complaining of chronic pelvic pain have been diagnosed as having this condition. Conversely endometriosis has been diagnosed in 20-50% of women who were completely asymptomatic, unaware that they had this pelvic pathology [1].

**3. Pathogenesis of endometriosis and gastrointestinal symptoms**

delayed or misdiagnosis (Figure 1.).

Lumen of rectosigmoid

posterior aspect of uterus, with obliteration of the Pouch of Douglas.

colon

pect of uterus, with obliteration of the Pouch of Douglas.

Cervix

symptoms [15].

Uterus

The enigmatic pathogenesis of endometriosis has led to the formulation of several hypotheses, but none have been proven conclusively. The elusiveness of its pathology has directed some workers to search beyond the female genital tract and concentrate their efforts at the gastro‐ intestinal system, the small and large bowel being in close anatomical proximity to the female genital tract (Figure 1.)[5,6,13]. The overlap of symptoms between both the gastrointestinal pathology and endometriosis influences clinical practice and in several women leads to

Sagittal Section: Retroposed Uterus due to Rectosigmoid Endometriosis

Adhesions between

Retrograde Menstrual Flow through Fallopian Tubes

> Endometriotic Implant

Adhesions

uterus and rectosigmoid colon due to endometriosis

Fallopian Tube

Functional Gastrointestinal Symptoms in Women with Pelvic Endometriosis

http://dx.doi.org/10.5772/56611

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Rectosigmoid

colon

Figure 1. Following retrograde menstrual flow through the Fallopian tubes, endometriotic deposits colonize adjacent peritoneal structures. The peritoneal structures involved include ovaries, utero-sacral ligaments and adjacent bowel especially the rectosigmoid colon. Following endometriotic deposition adhesion formation results. This may lead to a retroverted uterus due to endometriosis-induced adhesions between rectosigmoid colon and

**Figure 1.** Following retrograde menstrual flow through the Fallopian tubes, endrometriotic deposits colonize adja‐ cent peritoneal structures. The peritoneal structures involved include ovaries, utero-sacral ligaments and adjacent bowel especially the rectosigmoid colon. Following endometriotic deposition adhesion formation results. This may lead to a retroverted uterus due to endometriosis-included adhesions between rectosigmoid colon and posterior as‐

Physiological studies indicate that gastric emptying does not appear to be affected by the menstrual cycle. Abdominal symptoms related to the upper gastrointestinal tract appear more commonly during the follicular phase. During the follicular phase the transit time in the small bowel is longer. The normal menstrual cycle has no effect on gastric motility suggesting that gastric emptying does not change significantly between the follicular and luteal phases [14]. Almost 50% of women with irritable bowel syndrome report a perimenstrual increase in

Gastrointestinal symptoms appear more prevalent in women diagnosed with pelvic endome‐ triosis [2,3,]. Specific signs and symptoms result in frequent medical consultation are associ‐ ated with presence of endometriosis [4]. The anatomical separation between the gastrointestinal tract and the female genital tract may prima facie, appear disparate without any anatomical or physiological association. In a study by Muscat Baron et al [5,6] however, gastrointestinal symptoms such as heartburn and dyspepsia were significantly more com‐ monly found in women with endometriosis as compared to a control group. This was a prospective trial involving 57 menstrual women who had undergone laparoscopic examina‐ tion of the pelvis for a diverse number of abdominal and gynaecological symptoms. The women recruited to the study were asked a comprehensive questionnaire which included information on gastrointestinal symptoms, gynaecological symptoms, dietary intolerance and general symptoms. During laparoscopy 23 women were diagnosed as having pelvic endome‐ triosis while in the other thirty-four this diagnosis was excluded. Upper gastrointestinal symptoms such as heartburn and dyspepsia were found more commonly in the endometriosis group reaching statistical significance (p <0.001). These results posed the enquiry as to why two apparently anatomically distant systems, that is the gastrointestinal tract and the female reproductive system, should influence each other [5,6].

Women diagnosed with endometriosis have been shown to have concomitant irritable bowel syndrome symptoms. Ballard et al have shown that women with pelvic endometriosis were also diagnosed with irritable bowel syndrome (OR 1.6 [95% CI: 1.3-1.8]) [4]. Lower gastrointestinal symptoms in the form of diarrhoea and loose stools have been found more commonly found in women diagnosed with endometriosis. As opposed to the upper gastro-intestinal tract, both the small and to a greater extent the large bowel is in close proximity with the female genital tract. Both systems (intestinal and reproductive) throughout their physiological functioning are likely to influence each other [5,6].

It must be kept in mind that gastrointestinal symptoms commonly occur in the general population. Although estimates vary according to the diagnostic criteria used, 10–40% of the adult population experience heartburn and dyspepsia in Western countries. Gastro-oesopha‐ geal reflux disease increases with age, rising sharply beyond the fourth decade. More than half of the patients effected are aged between 45 and 64[7].

Dyspepsia also affects between 20% and 40% of the Western populations. A quarter of all cases of dyspepsia are though to be related to gastric and duodenal ulcers [8]. Several studies from the 1940's to the 1980's reported that population prevalence of 18%[9], 26%[10] and 31% [11] of people referred with dyspepsia were found to have peptic ulcers. Recently this percentage has fallen to around 10–15%[7]. Although mortality in people with gastrointestinal disorders is not raised compared with the general population, these disorders have a significant impact on quality of life. It has been shown that 75% of people with heartburn and dyspepsia suffered persistent symptoms and impaired quality of life over periods of 10 years or more; 30–50% never returned to work and were unable to carry out household tasks [12].
