Irritable bowel syndrome (IBS),a common functional gastrointestinal disorder,is characterized by altered bowel evacuation,bloating,and visceral pain in the absence of anatomical or biochemical abnormalities [1].Up to date,the etiologies of these symptoms are still not fully understood.The mateal separation (MS) model,rodent pups separated from the dam (3 h/day) during the neonatal period,has been found to display greater anxiety-like behavior,visceral hypersensitivity,increased fecal output,and higher levels of proinflammatory cytokines in adulthood [2],which may constitute a valuable experimental model to investigate the pathophysiology of IBS and to identify novel pharmacological targets.The rat model of IBS caused by MS was established in this study.All of the investigations conformed to the Guide for the Care and Use of Laboratory Animals published by the US National Institutes of Health.