Inflammatory Bowel Disease: Extraintestinal Manifestations and Cancer

Although ulcerative colitis and Crohn’s disease are idiopathic inflammatory bowel diseases (IBDs) that by definition affect the gastrointestinal tract, they are associated with a wide variety of systemic complications. Classically, such extraintestinal manifestations are defined as immune-mediated phenomena that affect the joints, eye, skin, or hepatobiliary tract, but they can be defined more broadly to include complications in other organ systems and complications that arise as a direct pathophysiologic consequence of extensive bowel inflammation or resection. This chapter reviews the most common extraintestinal manifestations, their relationship to activity of the underlying bowel disease, and their treatment.