Grouping ulcerative colitis with Crohn's disease (Inflammatory Bowel Disease) in a teaching seminar has historical support. The medical literature includes descriptions of both diseases in the latter half of the 19th century; they share many symptoms; in some instances, differentiating them may be very difficult; and the cause of each remains unknown. Furthermore, one member of a family may suffer with Crohn's disease while another has ulcerative colitis. And both processes are prone to the late complications of carcinoma at a site of previous involvement. Finally, the investigators and students of one disease have usually also contributed to the understanding of the other disease. The incidence of Crohn's disease seems to be increasing rapidly. This has been sug­ gested by reports from Sweden, the Netherlands, England, Scotland, and South Africa as well as the United States. Though methods of recording data vary, the increase is further supported by cases of greater virulence, still younger ages of onset, and more cases in the elderly. This is remarkable when we consider that fifty years ago, when the classic description from Mt. Sinai Hospital was being prepared, the disease was rare. Since the cause remains elusive, we must try to cope with this entity as skillfully as we can, with consideration of indications, and timing of drug and surgical intervention. The choice of forms of management has been controversial, even among the most experi­ enced physicians.