Shareholders of Lexicon (LXRX 0.60%) have been on a real roller-coaster ride with this stock, as the company at one point saw its drug LX2931 beaten by an incredible placebo that reduced patient symptoms by 49%, outperforming the drug itself at 44%. Now, however, the company's drug LX1033 has a chance to make up lost ground, as it has just received a fast-track designation from the FDA in its indication to treat irritable bowel syndrome. In this video, Motley Fool health care analyst David Williamson tells us whether this is going to be a major needle-mover for Lexicon and if there are other factors to watch with this company.