Clinical outcome of the first ten years of ulcerative colitis and proctitis.

269 patients with ulcerative colitis and a history of less than 6 months when first seen at St. Mark's Hospital in the decade 1966--75 have been followed for up to 11 years. The outcome has been correlated with the maximum extent of the disease observed within 3 months of presentation. 75 patients required hospital admission, 56 within a year of presentation. Extensive colitis developed in 60 patients. The cumulative probability of the disease being extensive was 21% +/- 3% at 5 years and 29% +/- 4% at 10 years. 25 patients required surgical treatment. The cumulative probability of operation was 8% +/- 2% at 5 years and 15% +/- 4% at 10 years. 19 patients are known to have died. The expected number of deaths was 19.2.