Recent developments on the role of Clostridium difficile in inflammatory bowel disease.

Clostridium difficile (CD), specifically its toxins, have been implicated as a risk factor for exacerbation of the inflammatory process in up to 5% of patients with ulcerative colitis or Crohnos disease. Typical evidence of colonic changes with CD infection, including pseudomembranous exudate, are often not present; however, a severe clinical course may result, including precipitation of toxic colitis and toxic megacolon. Recently, hypervirulent CD strains have been reported raising concern for a more severe disease process in patients with underlying inflammatory bowel disease. Moreover, small bowel involvement or CD enteritis has been increasingly described, usually in those with a history of a prior colectomy or total proctocolectomy for prior severe and extensive inflammatory bowel disease. Finally, refractory or treatment-resistant pouchitis may occur with CD infection.