(Reuters) - U.S. health regulators approved Salix Pharmaceuticals Ltd's drug to treat diarrhea in HIV/AIDS patients on antiretroviral therapy, a combination of medicines used to treat HIV infection.

Diarrhea is a common reason why HIV/AIDS patients discontinue or switch their antiretroviral therapies.

The drug, called Fulyzaq, is intended to be used in HIV/AIDS patients whose diarrhea is not caused by an infection from a virus, bacteria, or parasite.

Until now, there have been no therapies for HIV-associated diarrhea approved by the U.S. Food and Drug Administration.

(Reporting By Debra Sherman; Editing by David Gregorio)