[Definition and epidemiology of irritable bowel syndrome]

Irritable bowel syndrome (IBS) is characterized by abdominal discomfort, bloating and disturbed defecation in the absence of any identifiable physical, radiologic or laboratory abnormalities indicative of organic gastrointestinal disease. Diagnosis is based on the identification of symptoms according to Manning, Rome I and Rome II criteria and exclusion of alarm indicators. Approximately, 10-20% of the general population has IBS, and it affects female more often than male for unexplained pathophysiologic reasons. In Korea, it has been reported that the prevalence of IBS is 2.2-6.6% by Rome II criteria and 22.3% by Manning criteria. The health care-seeking population was only 28.6% of community population. Although most patients do not seek medical help, the disease accounts for huge costs for both patients and health-care systems and worsens patients' quality of life significantly.