October 17, 2006: A course of the antibiotic Rifaximin taken for ten days could treat Irritable Bowel Syndrome for as long as ten weeks, according to the latest study, the first of its kind that demonstrates the effect of antibiotic on the disease.
The report, published today in the Annals of Internal Medicine brings new hope to more than 20% Americans who suffer from IBS, a disease causing symptoms of bloating, gas, abdominal cramping, diarrhea, and constipation. The reason for this disease hitherto was doubted to be the overgrowth of normal bacteria in the gut. Hence the study was conducted using a “non-absorbable drug, one that would stay in the gut itself”.
Researchers at Cedars-Sinai Medical Center led by Dr. Mark Pimentel tested the drug with 87 participants who matched the criteria for IBS between December 2003 and March 2005. Each of them was given 1200 mg of Rifaximin, the FDA approved drug for traveler's diarrhea, or placebo per day for ten days.
They were analyzed for a further ten weeks, during which researchers found that there was more than 50% improvement in conditions among 37.2% Rifaximin users and 15% placebo users. However not much changes were recorded for the two main symptoms like diarrhea and constipation.
Lactulose breath tests performed on participants also showed that the most common symptom of IBS, bloating, was found to be due to bacterial fermentation that produced hydrogen and methane. This test gave researchers further evidence that overgrowth of bacteria could be the reason for IBS.
However, the study has invited criticism from experts, especially Dr. Douglas A. Drossman, MD, University of North Carolina Center for Functional GI and Motility Disorders, Chapel Hill. As per Drossman, IBS occurs due to a complex interplay of hypersensitive gut and brain.
“Pimentel's study does not prove that treating bacterial overgrowth helps and breath tests aren't reliable for diagnosing bacterial overgrowth,” says Drossman.
Pimentel has also admitted that although there are no side effects to this treatment mainly because the drug stays in the gut and does not mix with blood, similar studies should be conducted on a wider scale for longer duration over more number of people for a conclusion. At the moment, the result has brought in new hope in the treatment of IBS, more commonly known as spastic colon.
