Most studies of bowel habits havebeen conducted in Western countries. This study was conducted to estimate the epidemiology of constipation and the discrepancy between self-reported constipation and bowel habits in Koreans. Telephone interviews regarding bowel habits were conducted with a total of 1029 individuals in Korea, 15 years of age or older. Subjects were given a questionnaire which asked about bowel symptoms, sociodemographic associations, laxative use, and physician visits. Of all subjects 95.6% had a defecation frequency of between three per week and three per day. The prevalence was 16.5% for self-reported constipation, 9.2% for functional constipation (FC), and 3.9% for constipation-predominant irritable bowel syndrome (IBS-C). Of subjects' self-reporting constipation, proportions of FC and IBS-C were 21.8% and 23.5%, respectively. Of subjects excluding self-reported constipation, the proportion of FC was 6.8%. Prevalences of self-reported constipation and IBS-C were higher in females than in males (P < 0.001). Of subjects' self-reporting constipation, 8.2% used laxatives. We conclude that constipation is a common problem in the general Korean population.