Background: Functional constipation has important psychological elements.

Aim: To investigate the prevalence of functional constipation in an Asian population, and the interplay among functional constipation, anxiety/depression, perception and coping strategies.

Methods: An interview of 3282 patients was made by telephone survey. Constipation was diagnosed by Rome II criteria. Coping ability and anxiety/depression were assessed by validated questionnaires.

Results: Fourteen percent of the interviewees had constipation. Anxiety and depression scores were higher in constipated than in healthy subjects (P < 0.0001 and < 0.0001), and in female than male patients (P = 0.02 and < 0.0001). Patients who were aware of their symptoms perceived greater impact on their lives (P < 0.001). Frequent use of coping strategies associated with lower anxiety scores (P < 0.0001). Female were more frequently aware of the symptoms (P = 0.004), less frequently used coping strategies (P = 0.008). Regression analysis showed that female and high anxiety level were the independent factors for predicting the perception of constipation, whereas anxiety was the only independent factor for predicting the use of coping strategies.

Conclusion: Constipation associated with anxiety and depression is prevalent in the general Asian population. Female sex and anxiety are important aetiological factors in constipation, affecting perception and the use of coping strategies.