Rifaximin and Crohn's disease.

In a recent article, Longman and Swaminath analyzed our paper on the use of rifaximin in patients with moderately active Crohn's disease (CD). Here we report some considerations concerning their article. The exploratory post-hoc subgroup analysis showed that early-stage disease and, differently from that written by Longman and Swaminath, also colonic involvement seemed to be associated with a significant higher efficacy of rifaximin-EIR 800 mg twice daily. Early-stage disease is generally considered as the more easily treatable phase of CD, and the better response to rifaximin in Crohn's colitis is in accordance with the high concentration of bacteria in the colon. In addition, patients with C reactive protein level > 5 mg/L achieved remission more significantly than patients with normal values, thus suggesting that the symptoms were probably caused by inflammation instead of by non-inflammatory causes. We also analyze the role of rifaximin against gut bacteria and the clinical situations that could obtain the best results from antibiotics.