Research shows antibiotic prevents ibs symptoms for weeks after final dose

May 4, 2010

A targeted antibiotic provides effective and long-lasting relief of Irritable Bowel Syndrome symptoms, according to the results of two multisite Phase III clinical trials designed by Cedars-Sinai researchers. Rifaximin is the first drug treatment for IBS that relieves symptoms while it's being administered and continues to benefit patients after they stop taking the drug.

Researchers found that patients who took rifaximin not only experienced relief of their IBS symptoms, including specific symptoms of bloating, abdominal pain and stool consistency, while they were taking the antibiotic, but also that their relief was sustained over the 10 week follow-up period when no antibiotic was administered.

The results of the studies were presented at the Digestive Disease Week conference in New Orleans on May 3.

"These studies validate the role of altered in IBS," said Mark Pimentel, M.D., GI Motility Program director at Cedars-Sinai and the principal investigator of the clinical trail at Cedars. "These findings show that targeted antibiotics provide safe and long-lasting improvement for IBS patients."

IBS is the most common in the United States, affecting more than 20 percent of the population. Traditionally, patients with IBS have been described as having "constipation predominant," "diarrhea-predominant" or an alternating pattern of diarrhea and constipation. In addition to these symptoms, IBS patients often experience abdominal pain or cramps, excess gas or bloating, harder or looser stools than normal and visible abdominal distension.

Because the cause of IBS has been elusive, treatments for the disease have historically focused on relieving its symptoms through medications that either slow or speed up the digestive process. Earlier research conducted by Pimentel and colleagues documents a possible link between bloating, the most common IBS symptom, and bacterial fermentation by giving participants lactulose breath tests. The test monitors the level of hydrogen and methane - the gases emitted by fermented bacteria - on the breath. Those tests show elevated levels of those gases, indicating that small intestine bacterial overgrowth, or SIBO, may be a cause of IBS.

More than 1,200 patients participated in the Phase III, double-blind, multi-center studies of rifaximin, a nonabsorbable antibiotic that stays in the gut and is currently FDA-approved to treat traveler's diarrhea and hepatic encephalopathy. IBS patients with mild to moderate diarrhea and bloating were randomized to receive 550 milligrams of rifaximin or placebo for two weeks. Patients were then followed for an additional 10 weeks. Phase III trials are randomized studies on large patient groups to definitively demonstrate the safety and effectiveness of a new drug.

The findings support previous research by Pimentel indicating that IBS is caused by an overgrowth of bacteria in the gut.

"Even after you stop the antibiotic, the patients continue to feel better, which indicates that we did something to strike at what causes the condition," Pimentel said.

Explore further: A psychological approach to the management of irritable bowel syndrome

Related Stories

Allergic disease linked to irritable bowel syndrome

January 30, 2008

Adults with allergy symptoms report a high incidence of Irritable Bowel Syndrome (IBS), suggesting a link between atopic disorders and IBS according to a study published this month in Annals of Allergy, Asthma & Immunology, ...

FDA OKs Amitiza for treatment of IBS-C

April 30, 2008

The U.S. Food and Drug Administration announced approval of Amitiza (lubiprostone) to treat constipation associated with irritable bowel syndrome.

Bacterial phylotype alterations in irritable bowel syndrome

January 15, 2010

Irritable bowel syndrome (IBS) is a common gastrointestinal functional disorder that can greatly affect the patient's well being. Multiple interacting mechanisms, including alterations in the intestinal microbiota, are suspected ...

Recommended for you

How the finch changes its tune

August 3, 2015

Like top musicians, songbirds train from a young age to weed out errors and trim variability from their songs, ultimately becoming consistent and reliable performers. But as with human musicians, even the best are not machines. ...

Machine Translates Thoughts into Speech in Real Time

December 21, 2009

( -- By implanting an electrode into the brain of a person with locked-in syndrome, scientists have demonstrated how to wirelessly transmit neural signals to a speech synthesizer. The "thought-to-speech" process ...


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.