The protean manifestations of Crohn's disease.

Crohn's disease is a perplexing disease with a high rate of morbidity and complications. The incidence appears to be increasing. The cause is unknown, and response to medical therapy has been disappointing. Diagnosis may be very difficult and often is delayed. A high proportion of patients eventually require surgery, and an appreciable percentage will have recurrence of disease afterward. The prognosis in terms of responsiveness to medical therapy is believed to be poorer than the prognosis of ulcerative colitis. A national cooperative study to assess drug therapy prospectively is under way.