Inflammatory bowel disease (IBD) refers to chronic disorders of the small and/or large intestine characterised by inflammatory changes in the intestinal tissue. The two major types of inflammatory bowel disease are Crohn’s disease and ulcerative colitis.

Crohn’s disease usually affects the small intestine but may extend into the large intestine as well. Ulcerative colitis occurs only in the large intestine. The function of the small intestine differs from that of the large intestine; therefore, while the health consequences and treatment of Crohn’s disease and ulcerative colitis may be similar, there are important differences as well.