Background:Psychiatric disorders are common in irritable bowel syndrome (IBS). We conducted this study to investigate the relationship of IBS and their subtypes with some of psychological factors.Materials and Methods:A cross-sectional study was performed among 4763 staff of Isfahan University of Medical Sciences in 2011. Modified ROME III questionnaire and Talley Bowel Disease Questionnaire were used to evaluate IBS symptoms. Hospital Anxiety and Depression Scale and 12-item General Health Questionnaire were utilized to assess anxiety, depression and psychological distress. Logistic regression analysis was used to determine the association of psychological states and IBS in the total subject and both genders.Results:About, 4763 participants with mean age 36/58 ± 8/09 were included the 2106 males and 2657 females. Three thousand and seven hundred and seventy-six (81.2%) and 2650 (57.2%) participants were married and graduated respectively. Subtype analysis of IBS and its relationship with anxiety, depression and distress comparing the two genders can be observed that: IBS and clinically-significant IBS have higher anxiety, depression symptoms, and distress than the subject without IBS (P < 0.001). Women with IBS, have higher scores than men (P < 0.001). Compared to other subtypes, mixed IBS subtype has a higher anxiety, depression, and distress score.Conclusion:A high prevalence of anxiety, depression symptoms and distress in our subjects emphasize the importance of the psychological evaluation of the patients with IBS, in order to better management of the patients and may also help to reduce the burden of health care costs.