A common drug that has been on the US market for 50 years to treat gout could also reduce the symptoms of inflammatory bowel disorders and Crohn's disease, researchers said Wednesday.

The study in the journal Science Translational Medicine found that a strain of baker's yeast can live in the intestine and can worsen the pain, diarrhea and cramping associated with inflammatory bowel disorders, which have no cure and affect some 1.6 million Americans.

This yeast, known formally as Saccharomyces cerevisiae, "aggravated intestinal damage in mouse models of colitis," and also caused higher levels of uric acid in the gut, said the study.

But when mice were given allopurinol -- a drug that has been on the market since 1966 and is used to treat gout by reducing the amount of uric acid -- their intestinal disease went away.

Lead study author June Round of the University of Utah School of Medicine said some doctors have already prescribed allopurinol -- known as Zyloprim and Aloprim and available in generic form -- to patients with gout and Crohn's disease, and have noticed that it appeared to ease symptoms of both.

But these anecdotal observations should be followed up with clinical trials to gauge its effectiveness against inflammatory bowel disease, she told AFP.

"I think it is in the clinicians' hands at this point to just try it out in their patients," Round said, noting the drug has already been approved by the US Food and Drug Administration for use against gout.

"There is already some evidence that it might ameliorate symptoms and now we have identified the pathway so I think the doctors need to move forward with it."

Allopurinol is on the World Health Organization's list of essential medicines.

Side effects may include rash, fever, sore throat, vomiting and diarrhea.