Antibiotic May Aid Irritable Bowel
Xifaxan Reduces Bloating, May Attack Main IBS Cause
WebMD News Archive
Change of IBS Treatment?
Is Xifaxan a new treatment for IBS? Not yet. A larger study, looking at IBS
patients treated by their own doctors with Xifaxan, is already underway. Until
those results are known, Xifaxan is not an officially approved treatment for
But Pimentel says he's treated "thousands" of IBS patients with
Xifaxan -- and he says now the word is getting out.
"The gem here is you have a sustained effect in IBS. The larger, longer
studies will show how well this works," he says. "We've reported these
results at professional meetings, and it has changed the way IBS is treated.
Sixty percent of gastroenterologists in the country are starting to do it this
Pimentel says the average patient needs re-treatment every two or three
months, but that response varies greatly from patient to patient.
Controversy Over IBS Treatment
Not all experts are convinced that bacterial overgrowth is a root cause of
IBS, or that antibiotics are the best treatment. One of these experts is
Douglas A. Drossman, MD, co-director of the University of North Carolina Center
for Functional GI and Motility Disorders, Chapel Hill.
In an editorial accompanying the Pimentel study, Drossman notes that IBS is
a complex disorder that springs from the complex interplay of an oversensitive
gut and the brain.
Breath tests, he says, aren't reliable for diagnosing bacterial overgrowth.
And Pimentel's study, he says, does not prove that treating bacterial
Drossman is not impressed by Pimentel's finding that IBS patients reported
an average 36.4% improvement in the 10 weeks after treatment with Xifaxan,
while those given placebo treatment reported an average 21% improvement.
"Only bloating improved, and abdominal pain, diarrhea, and constipation
did not improve," Drossman notes. "The benefit of using antibiotics is
not fully proven and must be balanced with potential risks in terms of side
effects, high costs … and the need for recurrent treatment."
Pimentel says new studies now coming out will support the
bacterial-overgrowth theory of IBS. He does, however, say people with IBS have
"movement disorders of the small bowel." He is hoping that a drug to
promote movement in the small bowel will improve outcomes for IBS patients
treated with antibiotics.