Salix Pharmaceuticals, which won FDA approval for a gastrointestinal drug on May 26, gets a “strong buy” rating from Roth Capital.

Analyst Mark Taylor was reported by BusinessWeek as saying the drug approval was a “transforming event” for Salix. He upped his rating from “buy” and forecast the drug Xifaxan as producing $186 million in revenue by 2008.

Taylor kept a price target of $38 for the stock. Salix (Nasdaq: SLXP) was trading at $27.50 in afternoon trading on Wednesday, down 75 cents. It has a 52-week high of $35.46 and a low of $10.14.