Inflammatory bowel disease.

Inflammatory bowel diseases (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), are chronic, relapsing inflammatory condition of the gastrointestinal tract. CD and UC have distinct pathologic and clinical characteristics and despite the extensive amount of research conducted over the past decades, their pathogenesis remains still poorly understood. So far, the accepted dogma is that IBD results from dysregulated mucosal immune response to environmental factors in genetical susceptible hosts. Various components are implicated in the pathogenesis of IBD, including genetic susceptibility, environmental and microbial factors, intestinal epithelial cells and components of innate and adaptive immune system. Given the complexity of IBD, several different animal models of IBD have been developed during the last years. Animal models are very important tools to study the involvement of various factors in the pathogenesis of IBD and, importantly, to test new therapeutic options. This review examines some of the key components that have been found to be closely associated to IBD and describe the distinct features of some of the most important IBD models.