The diagnosis is usually confirmed by biopsies on colonoscopy. Fecal calprotectin is useful as an initial investigation, which may suggest the possibility of<unk> , as this test is sensitive but not specific for<unk> . Differential diagnosis Other<unk> s may cause an increased excretion of fecal calprotectin, such as infectious diarrhea, untreated coeliac<unk> , necrotizing enterocolitis, intestinal cystic fibrosis and neoplastic pediatric tumor cells. Conditions with similar symptoms as Crohn's<unk>  includes intestinal tuberculosis, Behçet's<unk> , ulcerative colitis, nonsteroidal anti-inflammatory drug enteropathy, irritable<unk>  syndrome and coeliac<unk> . Conditions with similar symptoms as ulcerative colitis includes acute self-limiting colitis, amebic colitis, schistosomiasis, Crohn's<unk> , colon cancer, irritable<unk>  syndrome, intestinal tuberculosis and nonsteroidal anti-inflammatory drug enteropathy. Liver function tests are often elevated in<unk> , and are often mild and generally return spontaneously to normal levels. The most relevant mechanisms of elevated liver functions tests in<unk>  are drug-induced hepatotoxicity and fatty liver. Classification The chief types of<unk>  are Crohn's<unk>  and ulcerative colitis (UC).<unk> s fall into the class of autoimmune<unk> s, in which the body's own immune system attacks elements of the digestive system. Accounting for fewer cases are other forms of<unk> , which are not always classified as typical<unk> : * Microscopic colitis subdivided into collagenous colitis and lymphocytic colitis * Diversion colitis * Behçet's<unk>  *Early Onset<unk>  * Indeterminate colitis No<unk>  specific markers are currently known in the blood, enabling the reliable separation of Crohn's<unk>  and ulcerative colitis patients. The way doctors can tell the difference between Crohn's<unk>  and UC is the location and nature of the<unk>  changes. Crohn's can affect any part of the gastrointestinal tract, from mouth to anus (skip lesions), although a majority of the cases start in the terminal ileum. Ulcerative colitis, in contrast, is restricted to the colon and the rectum. Microscopically, ulcerative colitis is restricted to the mucosa (epithelial lining of the gut), while Crohn's<unk>  affects the full thickness of the<unk>  wall ("transmural lesions"). Lastly, Crohn's<unk>  and ulcerative colitis present with extra-intestinal manifestations (such as liver problems, arthritis, skin manifestations and eye problems) in different proportions. In 10–15% of cases, a definitive diagnosis neither of Crohn's<unk>  nor of ulcerative colitis can be made because of idiosyncrasies in the presentation. In this case, a diagnosis of indeterminate colitis may be made. Although a recognised definition, not all centres refer to this.
Inflammatory bowel disease
Coeliac disease
Crohn's disease
Irritable bowel syndrome
Gastroenteritis
Ulcerative colitis
Anorexia nervosa
Chemical colitis