Overview of mouse models of inflammatory bowel disease and their use in drug discovery.

Inflammatory bowel disease (IBD), a condition that affects millions of individuals, encompasses two distinct conditions: Crohn's disease (CD) and ulcerative colitis (UC). CD is an inflammatory condition affecting any part of the digestive tract between the mouth and anus, but, most commonly, the ileum and colon. It is distinguished by the presence of granulomas in the mucosal tissue and patchy areas of transmural inflammation. UC is restricted to the colon and is manifest as continuous inflammation starting from the rectum and extending back towards the cecum. Inflammation in UC is primarily restricted to mucosal layers. Research is ongoing to understand the causality of these two diseases, and advances in understanding of their pathology have resulted from the variety of mouse models of IBD that have emerged since the early 1990s. Described in this unit are contemporary mouse models of these conditions and examples of their use in drug discovery.