Course and prognosis of Crohn's disease.

During the period 1938-70 there were 303 patients at the Radcliffe Infirmary, Oxford, diagnosed as suffering from Crohn's disease. Of these, 82 have been excluded, leaving 221 with a firm diagnosis. These patients have been divided into 'new cases', in which the disease was diagnosed at the Radcliffe Infirmary, and 'referred cases' in which the diagnosis was already made at the time of referral. In this series, there were three main sites of involvement: small intestinal, large intestinal, and both small and large intestinal. Ileocolitis was the commonest anatomical distribution. The disease showed progression to new, sites in a considerable number of the patients during the period under study. There was a fivefold increase of new cases between the first and third decades covered by the study and this applied equally to patients presenting as an acute abdomen, which supports the idea that the disease is truly increasing. Survival curves have been plotted and compared with expected survival curves. In terms of mortality, Crohn's disease emerges as a disease which becomes progressively more dangerous as the years go by, which is in sharp contrast with the findings in ulcerative colitis in which the main risk of dying is in the early years.