Irritable bowel syndrome (IBS) is a chronic, recurring disease affecting 10−20% of the US population. It is a multifaceted disorder, the exact cause of which is unknown, and is characterised by abdominal pain or discomfort, bloating and abnormal bowel function, resulting in chronic episodes of diarrhoea, constipation, or both in alternation. The burden of IBS on an individual can range from a mild inconvenience to severe debilitation, compounded by its unpredictability. As such, the disorder can have a broad and significant effect on patients' quality of life (QOL), controlling many aspects of their emotional, social and professional life. There is no known cure for IBS, and effective therapy remains a challenge. However, as the prevalence and impact of IBS becomes more well known, the medical community looks to new types of treatments for the disorder. Tegaserod [Zelnorm; Novartis], an indole carboxaldehyde derivative, is a selective serotonin4receptor partial agonist which targets receptors located throughout the GI tract. The agent is approved for use among patients with IBS whose primary bowel symptom is constipation, and has been shown in clinical trials to provide significant improvement in global IBS symptoms, and to be generally well tolerated. The effect of tegaserod on IBS patients' QOL, and the cost effectiveness of the drug, were assessed in two studies presented at the 7th Annual European Congress of the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) [Hamburg, Germany; October 2004]. Both the studies were funded by Novartis, with which some of the researchers were affiliated.