Alosetron is a very potent anti-diarrheal drug approved exclusively for relieving severe diarrhea caused by irritable bowel syndrome, and it is approved for women only. Before administering Alosetron, it is always worthwhile to check patient’s history and verify the order from the doctor. According to Medline, alosetron may cause life-threatening ischemic colitis (very low blood flow) in the stomach and intestines, which can lead to organ death and septicemia. It can also cause very severe constipation that requires hospital treatment. Ask the patient about present symptoms and previous medications he or she is currently taking.