Colitis, ulcerative

Plain film findings are minimal unless toxic megacolon occurs. Bowel with active disease is collapsed and has minimal faecal content. A double contrast enema shows fine mucosal ulceration (Fig.1), evenly distributed circumferentially, with progressive disease which starts at the rectum and extends proximally. While there is some overlap in the radiographic features of Crohn's disease and ulcerative colitis on barium enema, the typical finding in ulcerative colitis is that of mucosal granularity while in Crohn's, aphthous and fissure ulcers dominate, stricture formation occurs with both. Skip lesions, pseudodiverticula and fistula formation are features of Crohn's disease. A widened post-rectal space and reflux ileitis are seen in ulcerative colitis. With long standing disease the haustral pattern is lost and the colon becomes shortened and featureless. Pseudopolyps are rare in children. Colonic carcinoma seen in longstanding cases is not seen in children. Sacroiliitis and other arthropathy is occasionally present. When toxic megacolon occurs, clinically the children become extremely ill. The colon dilates so that the calibre is at least 5 cm and with some thickening of the bowel wall. Complications include perforation and peritonitis. Backwash ileitis - involvement of the terminal ileum - may occur in severe cases if there is an incompetent ileocaecal valve. See colitis ulcerative

HC