Involvement is limited to the colon and rectosigmoid area in a continuous pattern without skip areas.
Diagnosis is by endoscopy and biopsy or contrast studies showing superficial ulcerations.
Carcinoembryonic antigen is elevated in chronic cases and is not suggestive of the development of a carcinoma. Bowel ANCA may be positive. As with Crohn's disease, contrast studies are contraindicated in those with acute disease, since barium may induce a toxic megacolon. Complications include those listed for Crohn's disease . Additionally the development of a toxic megacolon or anemia from hemorrhage is more common with ulcerative colitis as is the development of malignancy.