Long-term follow-up study of ulcerative colitis in Japan.

To clarify the long-term prognosis of Japanese patients with ulcerative colitis, we investigated the cumulative colectomy rate and the survival rate, and compared the results with reports from Western countries. The subjects were 778 patients who had visited 8 hospitals from 1973 to 1990. A total of 114 of the 778 patients (14.7%) had required colectomy and 21 (2.7%) had died. These rates were higher in the patients who had total colitis, and in those who had acute fulminant type of severe type. There were no significant differences in these rates according to age of onset (under 29 years, 30-49 years, and more than 50 years). The cumulative colectomy rate increased rapidly within 2 years after onset. Thereafter, the rate increased gradually, by 1%-2% per year. In patients with total colitis, 14.1% required colectomy within 2 years. The age at onset had no effect on this rate. The cumulative survival rate decreased gradually throughout the first 10 years, the rate being 96.2% in the 10th year. No deaths occurred in the 11-18th years after onset. Despite our inclusion of more patients with total or severe colitis, our results were similar to or slightly superior to those reported from Western countries; this may be attributed to a temporal bias.