On Jan 9, 2011 the CBC news posted an article describing new research

study results for relief of irritable bowel syndrome symptoms. Two studies showing 41 per cent of patients taking the antibiotic rifaximin reported substantially improved symptoms for up to 10 weeks compared with placebo. The two studies involved 1260 patients with mild to moderate IBS without constipation. Patients were given either a placebo or 550 mg of rifaximin three times a day for two weeks. Lead researcher Dr. Mark Pimentel of Cedars-Sinai Medical Center, noting the improved symptoms lasted past the two weeks, remarked “we’ve actually touched on the cause of IBS, as opposed to just covering up symptoms.” Results from other studies investigating overgrowth of bacteria in the gut as the cause of IBS have been mixed. Dr. Jan Tack from the University of Leuven in Belgium states that the response to rifaximin in these studies is novel and important as well as within the range seen with other effective IBS treatments. Salix Pharmaceuticals, the makers of rifaximin, are seeking to expand the drug’s use to IBS. Rifaximin is approved for traveller’s diarrhea and complications of liver disease. The studies were paid for by Salix, some researchers were Salix employees, and others received consulting fees from the company. Cedars-Sinai holds a patent on the use of rifaximin for IBS.