Irritable bowel syndrome (IBS) is one of the most common functional gastrointestinal disorders(FGIDs) characterized by chronic abdominal pain or discomfort, which is associated with changes in stool frequency and/or form. Rome II criteria for IBS was used widely in research and practice. Besides, Rome III criteria was recently published. Because IBS is a frequent disease, the spread of Rome III criteria will play an important role of pathophysiological study and new therapy in gastrointestinal medical care.