Health Team

Antibiotic offers relief from irritable bowel syndrome

Posted May 14, 2010 3:56 p.m. EDT
Updated May 17, 2010 6:41 p.m. EDT


— Researchers believe they have a way to control irritable bowel syndrome, a painful digestive disorder that affects about 20 percent of adult Americans.

Amy McMahon, 50, knew something was wrong when she began to bloat uncomfortably. But it took nine months of failed treatments and testing before she was diagnosed with IBS.

"My stomach was distended, I'm going to say, (like I was) seven months' pregnant, " she said. "It was really awful. By midday, I'd have to lie down."

Then McMahon became part of study of the antibiotic rifaximin being conducted by Dr. Mark Pimentel, at Cedars Sinai Medical Center in New York. Of the 1,200 IBS patients in the study, 40 percent said they felt better and their symptoms went away when they were taking the drug.

Rifaximin targets bacteria in the small intestine.

"It's not bad bacteria. It's that they don't belong in the small intestine," Pimentel said.

Pimentel and his researchers were the first to figure out that bacteria was causing IBS. Until then, doctors would often link IBS with stress and treat patients with antidepressants. Medications could lessen the diahrrea and constipation associated with IBS but were not a lasting treatment.

"This is the first antibiotic, this rifaximin, that treats IBS," Pimentel said. "(Patients) get better and stay better. Every other therapy we've used, as soon as you stopped it, they get sick again."

The Food and Drug Administration has not approved rifaximin as an IBS treatment, but doctors can chose to prescribe it for the condition.

McMahon said that three years after taking part in the clinical trial, she's still symptom free.

"I'm feeling really good," she said.