*4.5.2 Ulcerative colitis*

UC is a chronic inflammatory disease of the colon characterized by a continuous mucosal inflammation extending from the rectum to the proximal colon with a variation in the degree of extent [194]. Colitis of the colon and rectum is characterized by continuous areas of inflammation and ulceration, without any segments of normal tissue present. It typically affects only the innermost lining [195]. Tenesmus and bloody diarrhea are hallmark symptoms of UC. The patients also report mild tenderness, lower abdominal cramping as well as fatigue due to the blood loss. Even though the etiology of UC remains unclear, increasing evidence suggests it may be an autoimmune condition [196]. The disease can develop at any age but is most commonly diagnosed before the age of 30 [197]. It has been reported that the prevalence of UC varies globally between 2.42 and 298.5/100,000, with the highest incidence occurring in North America and Northern Europe [154]. UC affects both sexes equally, and it affects all ethnicity with 3−6 more prevalence in Jewish people [198]. A "Western diet," left-handedness, and depression may increase risk for UC [199–203]. As part of

*Autoimmune Diseases of the GI Tract Part I: Etiology and Pathophysiology DOI: http://dx.doi.org/10.5772/intechopen.106184*

the diagnosis of UC, it was recommended to test for CBC to check for intestinal blood loss and anemia [195]. Additionally, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), fecal lactoferrin, and fecal calprotectin levels are used to assess inflammation [198]. Nutritional status and deficiencies are assessed using serum albumin, iron studies, and vitamin B12 levels. UC is usually confirmed by sigmoidoscopy or colonoscopy if it has not been ruled out. It has a hallmark of the presence of continuous colonic inflammation characterized by erythema, loss of normal vascular pattern, granularity, erosions, friability, bleeding, and ulcerations, with a clear distinct demarcation between inflamed and non-inflamed bowel (**Table 1**) [198].
