[Clostridium difficile infection and chronic inflammatory bowel disease.]

Patients with IBD are at increased risk of developing Clostridium difficile (CD) infection and have worse outcomes, including higher rates of colectomy and death, and experience higher rates of recurrence. However, it is still not clear whether CD is a cause of IBD or a consequence of the inflammatory state and of intestinal dysbiosis. The association between IBD and CD may be due to different factors, such as drugs that are used for the treatment of IBD, including repeat courses of antibiotics, that might alter the intestinal flora and promote colonization, altered immune and nutritional status, frequent hospitalizations, and even genetic predisposition. It has been suggested that up to 20% of IBD flares were associated with testing positive for CD and retrospective studies demonstrated doubling of the infection incidence among patients with Crohn Disease, and a 3-fold increase among those with Ulcerative Colitis. They have also shown that the CD infection incidence among IBD patients is estimated as being 3-fold higher than that in the general population. Decreased intestinal microbial diversity along with an inadequate immune response is thought to play a causative role in the development of CD infection.