Lotronex is a prescribed medication given only to women with severe diarrhea-predominant irritable bowel syndrome (IBS). Indications of severe are as follows. Chronic IBS lasting 6 months or longer or non-reactive to conventional treatments. Confirmation is also required that the sufferer is free of any anatomic or biochemical abnormalities of the gastrointestinal tract. The main ingredient in Lotronex is alosetron hydrochloride. Lotronex is an orally administered drug and is available in both 0.5 and 1 mg tablets. Though infrequently, the following severe adverse reactions have been reported in connection with the use of Lotronex. Severe constipation and ischemic colitis which have required hospitalization, and in some rare cases, blood transfusions and surgery. There have also been some rare cases of death reported. Patients who develop severe constipation or ischemic colitis should discontinue use of Lotronex immediately.