CLINICAL COURSE OF COLORECTAL CROHNS-DISEASE - A 35-YEAR FOLLOW-UP-STUDY OF 507 PATIENTS

Background & Aims: Crohn's disease (CD) confined to the colon and rect um is an increasing clinical entity. The aim of this study was to asse ss the features and clinical course of colorectal CD. Methods: This wa s a retrospective cohort study of 507 patients in whom colonic or rect al CD had been diagnosed between 1955 and 1989. Results: Colonic distr ibution was segmental in 40%, total in 31%, and left-sided in 26%. Per ianal/rectal fistulas occurred in 37%. In patients who attained clinic al remission, the 5-year cumulative relapse rate after diagnosis was 6 7% (95% confidence interval [CI], 62-72). At the initial presentation of CD, the frequency of major surgery decreased from 24% to 14% (P < 0 .005) over time. Still, the overall long-term probability of major sur gery after 10 years was unaltered (49% vs. 47%). The presence of fistu las increased the probability of surgical resection (relative risk [RR ], 1.7 [95% CI, 1.3-2.2]), whereas left-sided disease was associated w ith a decrease (RR, 0.6 [95% CI, 0.4-0.8]). Twenty-four percent of the patients developed inflammation in the small bowel. The cumulative ri sk for a permanent ileostomy was 25% (95% CI, 21-29) 10 years after di agnosis. Conclusions: Colorectal CD is an increasing entity carrying s ubstantial morbidity. Half of the patients will undergo surgical resec tion within the first 10 years, and half of those will ultimately unde rgo ileostomy. Changed management at diagnosis has not affected the lo ng-term probability of resection.