Abstract： Objective To investigate the prevalence and related risk factors of irritable bowel syndrome (IBS) among the service men of a certain unit.Methods Questionnaire forms were developed in accordance with Rome Ⅲ criteria.Then,by hierarchy multiple regression analysis and random cluster sampling method,questionnaire was conducted in a population of 2 357 servicemen with an age range from 17-45 years.To exclude organic diseases in the colon,patients with obvious symptoms received colonoscopy or barium enema detection to identify the incidence of the disease.Univariate and multivariate analyses of the risk factors associated with prevalence of the disease were performed accordingly.Results According to Rome Ⅲ criteria,the prevalence of IBS among the servicemen of a certain unit was 17.14％.Hierarchy multiple regression analysis indicated that significant differences in the incidence of the disease could be noted in the servicemen with different ages,different jobs,and different body mass indexes (BMI) (P ＜ 0.05).Conclusions IBS is a common disease among the service men of a certain unit,with relatively higher prevalence.For this reason,service men should deepen their knowledge and take preventive measures against the disease.