The idiopathic inflammatory bowel diseases (IBD) comprise a spectrum of disorders that are marked by the presence of chronic inflammation of the gastrointestinal tract which cannot be ascribed to a specific pathogen (1, 2). At one end of the spectrum is ulcerative colitis, a disease that affects the large bowel exclusively and which is characterized by mucosal ulceration, superficial inflammatory-cell infiltration of the bowel wall, and, in extensive long-standing cases, neoplastic transformation. Prominent symptoms in this form of IBD include severe bloody diarrhea, pain on defecation, weight loss, and, in children, growth failure. At the other end of the spectrum is Crohn's disease (regional enteritis or regional ileitis), a disease that in contrast to ulcerative colitis can affect any part of the alimentary canal, from the mouth to the rectum, but which most commonly involves the terminal ileum and the ascending colon. In this condition, the major pathology consists of a focal, transmural inflammatory, cell infiltration that is sometimes granulomatous in character and which may be complicated by intestinal strictures, fistula formation, and perforation, Symptoms that commonly occur in Crohn's disease include abdominal pain of a cramping nature and systemic complaints such as fever