Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started
My Medicine

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Irritable Bowel Syndrome (IBS) Health Center

Font Size

Antibiotic May Aid Irritable Bowel

Xifaxan Reduces Bloating, May Attack Main IBS Cause

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 IBS.

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 way."

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 overgrowth helps.

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.

1 | 2

Today on WebMD

filling glass of water from faucet
Prevention strategies to try.
stomach ache
From symptoms to treatments.
Causes, symptoms, and treatments.
worried mature woman
Are they related?
IBS Trigger Foods
Supplements for IBS What Works
IBS Symptoms Quiz
digestive health
gluten free diet
digestive myths
what causes diarrhea
man with abdominal pain

WebMD Special Sections