No pathogenic Clostridium difficile infection is found in irritable bowel syndrome patients fulfilling Rome III criteria

Background: The infection rate of Clostridium difficile (C difficile) is increasing in recent years, and the clinical presentation of some patients with mild C. difficile infection is similar to diarrhea-predominant and mixed type irritable bowel syndrome (IBS-D and IBS-M). However, it is really difficult to detect C difficile infection by the usual methods. Aims: To assess whether a portion of the IBS-D and IBS-M patients fulfilling the Rome III criteria is related to pathogenic C. difficile infection or C difficile carrying state. Methods: One hundred and twenty consecutive patients fulfilling the Rome III criteria for IBS-D and IBS-M were prospectively enrolled in this study. Stool samples were collected and tested by VIDAS® C difficile toxin A II (CDA2) kit with enzyme-linked fluorescent assay (ELFA) for toxin A. Samples with a suspicious result were further tested with CDA2 blocking (CDB) assay to improve the detection rate. Results: None of the IBS-D and IBS-M patients was positive for stool C difficile toxin A. Conclusions: IBS-D and IBS-M patients fulfilling the Rome III criteria have no pathogenic C difficile infection or carrying of C. difficile in this study. In these patients, routine use of metronidazole or other antibiotics is not recommended.