Double Trouble - Clostridium difficile Infection in Patients with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) patients appear to be at an increased risk for Clostridium difficile infection (CDI), but there are unresolved questions as to the diagnostic approach, true clinical impact and optimal management of these challenging patients. In this clinically oriented review article, we will focus on several uncertainties and misconceptions. A critical appraisal of the literature shows that it is still unclear whether CDI adversely impacts the course of an IBD flare or is merely a bystander organism, whose colonic colonisation marks patients with more severe underlying IBD and/or profound immunosuppression. Moreover, diagnosis of CDI in IBD is fraught with methodological problems and repeat testing after a negative enzyme-linked immunosorbent assay (ELISA) result may worsen this situation by increasing the rate of false-positive results due to the low positive predictive value of available assays. Finally, the treatment of CDI in flaring IBD remains controversial and cited evidence to support vancomycin over metronidazole is based on studies carried out in non-IBD populations. IBD experts are also divided in their opinion with respect to the need to withhold adjunct immunosuppressive treatment for flaring IBD-CDI patients, or conversely, to intensify it for presumed simultaneous IBD inflammatory activity. Further evidence from controlled trials is eagerly awaited in order to resolve these clinical dilemmas.