Prospective study of outpatients with extensive colitis

171 patients with extensive colitis have been followed up as outpatients for periods up to seven years between 1966 and 1973. The mean length of follow-up was 3.3 years. 7 patients have died compared with the expected mortality of 4.83, giving an excess mortality of 0.003 per patient-year. 3 patients have developed carcinoma of the large bowel; they remain well seven, six, and two years after operation. In all 3, epithelial dysplasia was observed on rectal mucosal biopsy, and no patient in this series has developed carcinoma without this abnormality being present. 11 other patients had epithelial dysplasia on rectal biopsy; 4 of these underwent colectomy without evidence of carcinoma in the operative specimen. 29 patients underwent colectomy without mortality, 7 during a severe attack of colitis, the remainder electively. These results suggest that patients with quiescent extensive colitis can be managed conservatively with relative safety provided that close supervision is maintained.