UPDATE 1-Salix says FDA denies approval of bowel drug

* Says FDA raises concerns over manufacturing facility

* Says FDA did not request for additional clinical trials

April 28 (Reuters) - Salix Pharmaceuticals Ltd (SLXP.O) said U.S. health regulators declined to approve its experimental drug for the treatment of a kind of inflammatory bowel disease in adults.

The company said the U.S. Food and Drug Administration issued a complete response letter, raising concerns over a manufacturing facility for Giazo.

Salix said the regulator did not request for any new pre-clinical or clinical trials for the drug.

The company, which was recently warned by the FDA regarding misleading sales advertisement for its Metozolv tablets, used in the treatment of gastroesophageal reflux disease, said the concerned manufacturer has responded to the FDA and is working to resolve the matter.

Shares of Salix were trading up 1 percent at $39.10 in early morning trade Wednesday on Nasdaq. (Reporting by Krishnakali Sengupta in Bangalore; Editing by Maju Samuel)