Abstract
What is it, and who gets it? Ulcerative colitis is a form of inflammatory bowel disease characterised by diffuse inflammation of the colonic mucosa. It affects the rectum and extends proximally along a variable length of the colon. The disease can be categorised as left sided colitis (inflammation up to the splenic flexure) or extensive colitis (inflammation beyond the splenic flexure). These categories are useful when formulating treatment options and planning the timing of surveillance colonoscopy, which is used to detect and prevent colorectal carcinoma. Colitis affects about one in 1000 people in the Western world.