A 38-year-old man had a history of inflammatory bowel disease starting at age 30, and treated with 5-ASA derivatives. At age 36 he underwent ileocecal resection during surgery for presumed appendicitis. He was admitted this time with signs of intestinal obstruction. He failed to respond to high dose steroids, and colonoscopy showed a high grade stricture at the splenic flexure with exophytic growth near the stricture. Biopsy specimens showed high grade dysplasia and carcinoma in situ.