Salix Pharmaceuticals (NASDAQ: SLXP) reported good news from a phase 3 trial of Xifaxan in patients with irritable bowel syndrome with diarrhea (IBS-D), an additional potential indication for a drug that turned in nearly $650 million in sales last year.

Good news is nice, and given that analysts are estimating over $1 billion in annual peak sales for Xifaxan based on label expansions, it's nice to see good data coming through.

But is the stock a good investment? In the video below, Motley Fool health care analysts Michael Douglass and David Williamson give their take.