Tehran University of Medical Sciences Journal of Modern Rehabilitation 2538-385X 17 2 2023 04 01 181 187 Tuba Mahmoudzadeh Department of Physiotherapy, Faculty of Rehabilitation, Tabriz University of Medical Sciences, Tabriz, Iran. Fariba Ghaderi Department of Physiotherapy, Faculty of Rehabilitation, Tabriz University of Medical Sciences, Tabriz, Iran. Mohammad Asghari Jafarabadi Department of Statistics and Epidemiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran. Bita Sepehri Liver and Gastrointestinal Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. Hakimeh Adigozali Department of Physiotherapy, Faculty of Rehabilitation, Tabriz University of Medical Sciences, Tabriz, Iran. 2021 09 21 2021 11 29 Introduction: Chronic constipation is one of the most common complaints of patients in developed countries, which affects 2 to 28% of the world’s population and alters patients’ quality of life extensively. This study aimed to determine the validity and reliability of the Persian version of the comprehensive constipation questionnaire. Materials and Methods: The comprehensive constipation questionnaire was translated into Persian, and its back-translation was confirmed after evaluating the content validity ratio index (CVR) based on Lawshe table (CVR≥0.62). The content validity of the questionnaire was assessed by the content validity index, followed by examining its reliability by Cronbach alpha and test-re-test reliability using the intra-class correlation coefficient (ICC). A total of 100 patients with chronic constipation completed the questionnaire. Results: Content validity was confirmed in the range of 0.84 to 1.00, and the Cronbach alpha values in the range of 0.90-1.00 were acceptable. In this questionnaire, was ICC in the range of 0.76-0.99 which indicates a level of good to excellent reliability of the questionnaire. Also, the results of the factor analysis were confirmed at a moderate level Kaiser Meyer Olkin test (KMO>0.6) and Bartlett test (P<0.05) by extracting a 1-factor solution. Conclusion: The Persian version of the comprehensive constipation questionnaire had acceptable validity and reliability and seems to be an effective tool to evaluate patients with constipation. https://jmr.tums.ac.ir/index.php/jmr/article/view/557