Fistulizing Crohn's disease

Crohn's disease (CD), characterized by idiopathic transmural inflammation anywhere along the gastrointestinal (GI) tract, is increasing in incidence worldwide for unknown reasons. The transmural inflammation can result in inflammatory, stricturing, or penetrating (fistulizing) phenotypes, all of which are notoriously difficult to treat. When a patient has inflammatory disease, medical immunosuppressive therapy with corticosteorids, immunomodulators, or biologics may be helpful before a fibrostenotic disease process starts. Once there is fibrosis, bowel damage is difficult to reverse, and proximal fistulizing disease may develop. Fistulizing disease, one of the most notoriously difficult disease manifestations can also occur anywhere along the GI tract, affecting portions as proximal as the duodenum or as distal as the anus with perianal and rectovaginal fistulas (RVFs).