Ulcerative colitis

Chronic inflammation and ulceration of the lining of the colon and rectum, or, especially at the start of the condition, of the rectum alone. The cause of ulcerative colitis is unknown, but the condition is most common in young and middle-aged adults. The main symptom of ulcerative colitis is bloody diarrhoea; and the faeces may also contain mucus. In severe cases, the diarrhoea and bleeding are extensive, and there may be abdominal pain and tenderness, fever, and general malaise. The incidence of attacks varies considerably. Most commonly, the attacks occur at intervals of a few months. However, in some cases, there may be only a single episode. Ulcerative colitis may lead to anaemia, caused by blood loss. Other complications include a toxic form of megacolon, which may become life-threatening; rashes; aphthous ulcers; arthritis; conjunctivitis; or uveitis. There is also an increased risk of cancer of the colon developing (see colon, cancer of). A diagnosis is based on examination of the rectum and lower colon (see sigmoidoscopy) or the entire colon (see colonoscopy), or is made by a barium enema (see barium X-ray examination). During sigmoidoscopy or colonoscopy, a biopsy may be performed. Samples of faeces may be taken for laboratory analysis in order to exclude the possibility of infection by bacteria or parasites. Blood tests may also be needed. Medical treatments of ulcerative colitis include corticosteroid drugs and sulfasalazine and its derivatives. Colectomy may be required for a severe attack that fails to respond to other treatments, or to avoid colonic cancer in those people who are at high risk.