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 Crohns disease affects the full thickness of the bowel wall ("transmural lesions"). Lastly, Crohns disease 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 Crohns disease 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. Treatment
Surgery
CD and UC are chronic inflammatory diseases, and are not medically curable. However, ulcerative colitis can in most cases be cured by proctocolectomy, although this may not eliminate extra-intestinal symptoms. An ileostomy will collect feces in a bag. Alternatively, a pouch can be created from the small intestine; this serves as the rectum and prevents the need for a permanent ileostomy. Between one-quarter and one-half of patients with ileo-anal pouches do have to manage occasional or chronic pouchitis.Surgery cannot cure Crohns disease but may be needed to treat complications such as abscesses, strictures or fistulae. Severe cases may require surgery, such as bowel resection, strictureplasty or a temporary or permanent colostomy or ileostomy. In Crohns disease, surgery involves removing the worst inflamed segments of the intestine and connecting the healthy regions, but unfortunately, it does not cure Crohns or eliminate the disease.
Differential diagnosis
Other diseases may cause an increased excretion of fecal calprotectin, such as infectious diarrhea, untreated coeliac disease, necrotizing enterocolitis, intestinal cystic fibrosis and neoplastic pediatric tumor cells.Conditions with similar symptoms as Crohns disease includes intestinal tuberculosis, Behçets disease, ulcerative colitis, nonsteroidal anti-inflammatory drug enteropathy, irritable bowel syndrome and coeliac disease.Conditions with similar symptoms as ulcerative colitis includes acute self-limiting colitis, amebic colitis, schistosomiasis, Crohns disease, colon cancer, irritable bowel syndrome, intestinal tuberculosis and nonsteroidal anti-inflammatory drug enteropathy.Liver function tests are often elevated in inflammatory bowel disease, and are often mild and generally return spontaneously to normal levels. The most relevant mechanisms of elevated liver functions tests in IBD are drug-induced hepatotoxicity and fatty liver. Classification
The chief types of inflammatory bowel disease are Crohns disease and ulcerative colitis (UC). Inflammatory bowel diseases fall into the class of autoimmune diseases, in which the bodys own immune system attacks elements of the digestive system.Accounting for fewer cases are other forms of IBD, which are not always classified as typical IBD:
Microscopic colitis subdivided into collagenous colitis and lymphocytic colitis
Diversion colitis
Behçets disease
Early Onset IBD
Indeterminate colitisNo disease specific markers are currently known in the blood, enabling the reliable separation of Crohns disease and ulcerative colitis patients. The way doctors can tell the difference between Crohns disease and UC is the location and nature of the inflammatory changes. Crohns 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.