Irritable bowel syndrome (IBS) is a gastrointestinal disorder characterized by chronic abdominal pain associated with altered bowel habits. Since the prevalence of IBS is very high and thus, involves elevated health-care costs, treatment of this condition by methods other than prescribed medicines could be beneficial. beta-(1,3)-D-glucan with beta-(1.6) branches (beta-glucan) has been used as a nutritional supplement for many years. In this study, we examined the effect of beta-glucan on fecal pellet output and visceral pain response in animal models of IBS. Oral administration of beta-glucan suppressed the restraint stress- or drug-induced fecal pellet output. beta-Glucan also suppressed the visceral pain response to colorectal distension. These results suggest that beta-glucan could be beneficial for the treatment and prevention of IBS. (C) 2012 Published by Elsevier Inc.