Background: Chronic constipation is a common, self-reported, and symptom-based disorder which can significantly influence an individual’s health-related quality of life and imposes several financial costs. Aims: The present study aimed to evaluate the effect of water consumption, fiber intake, and physical activity (PA) on constipation, and which one is more critical by considering the mediating effect of BMI. Subjects and Methods: This cross-sectional study involved 400 older adults in 2019 referring to the comprehensive health service centers in Karaj, the capital of Alborz province. The data were collected using the questionnaires of demographic and anthropometric characteristics, PASE (Physical activity for elderly), fluid intake, FFQ (Food Frequency questionnaire), Wexner constipation, and Persian lifestyle questionnaire analyzed using SPSS and LISREL software. Results: Based on the final fitted model, PA is the most critical constipation-related factor compared to the fluid intake and fiber consumption. In addition, fiber consumption is the second crucial factor affecting constipation, and there is a negative association between constipation and fiber intake. Conclusion: As price is one of the barriers to fiber consumption among the elderly, the recommendation to do physical activity such as walking to solve constipation is efficient and inexpensive for individuals with different socio-economic status.
Keywords: Physical activity, Wexner constipation, fiber consumption, elderly, Iran.