Purpose: Constipation is a common entity in society with various factors in the etiology. In this study, we evaluated the role of anal sphincter pressure of patients who refer to surgery clinic with complaint of constipation. Methods: Sixty patients who refer to surgery clinic with complaint of constipation and were diagnosed with constipation due to Rome III criteria between July 2010 and September 2014. These patients were evaluated with defecography and were divided into 2 groups based on presence of rectocele. Both groups’ anal sphincter pressures were evaluated using anal manometry and findings were compared. Results: The patients with rectocele and without rectocele using defecography were inspected with anal manometry regarding resting tone pressure, squeeze pressure, maximum squeeze pressure and simulated defecation response pressure, first sensation volume, urge sensation volume, and maximum tolerable volume. Results were compared and no significant difference was found regarding groups with rectocele and without rectocele (P > 0.05). Conclusion We have proved the hypothesis arguing that increased sphincter pressures do not play a role in the formation of rectocele by inducing an obstruction and the formation of dilation in proximal bowel, and demonstrated that the presence of rectocele is not dependent on an increase in sphincter pressures.