Crohn's disease, ulcerative colitis, carcinoma of the colon, diverticulitis and constipation. An illustration of five disorders in the intestine. At lower centre, where the ileum (small intestine) meets the colon (large intestine), a dissected area shows Crohn's disease: with ulceration on the intestine wall. Upper right, the descending colon is affected by ulcerative colitis, a disease which can severely relapse, and which is associated with colonic cancer (at lower right) seen as a blockage in the colon due to tumours. Near this, growths on the outer colon wall show diverticulitis (CDD), associated with abscess formation. At bottom, the rectum has impacted faeces in constipation.