It’s not a topic people like to talk about, but several million Americans suffer from IBS, or irritable bowel syndrome.

No one drug treats all of the symptoms, but a new study published in the New England Journal of Medicine found that a drug made in the Triangle might be the answer.

Patients with IBS typically complain of symptoms such as abdominal cramping and pain, bloating and sometimes diarrhea and constipation. Doctors can prescribe medications to treat the individual symptoms.

“What we are missing and we don’t have available are medications that target the underlying abnormalities,” said UNC Hospitals gastroenterologist Dr. Yehuda Ringel.

Ringel said that’s because doctors aren’t sure what those abnormalities are. He co-authored a large study of the antibiotic Xifaxan on IBS patients without constipation.

The drug is made by Salix (Nasdaq: SLXP), a pharmaceutical company based in Morrisville. It’s unlike other antibiotics in that it goes straight to the large intestine without being absorbed by the bloodstream. It fights bacterial infections such as travelers’ diarrhea caused by E.coli.

Salix announced the study results after the markets closed Wednesday. Shares had ended the day at $47.24, up 51 cents.

IBS study participants received 550 milligrams of the drug, three times a day for two weeks.

“The interesting finding is first that the antibiotic helped with these conditions, and the second is that the effect lasted for 10 weeks after discontinuation of the medication,” Ringel said.

Xifaxan, or the generic form Rifaximin, is not approved by the Food and Drug Administration for treating IBS. However, the study results support the idea that intestinal microbiota, or gut bacteria, might be the underlying cause of the disorder and that the drug might offer relief for many patients who struggle with IBS.

Ringel says more research is needed to determine how and when the antibiotic should be used for IBS patients.

* Reporter: Allen Mask, M.D.
* Producer: Rick Armstrong
* Web Editor: Kelly Hinchcliffe

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