Functional constipation and outlet delay: A population-based study

Background: Chronic constipation may result from many mechanisms including colonic inertia or rectosigmoid outlet delay, but risk factors for constipation in the community are poorly defined. The prevalence of and predictors for symptoms consistent with functional constipation and outlet delay were estimated. Methods: An age- and gender-stratified random sample of 1,021 residents of Olmsted County, MN, aged 30-64 years, was mailed a valid self-report questionnaire; 835 responded (82%). These respondents were mailed a second questionnaire 12-20 months later that gathered data on symptoms compatible with functional constipation and outlet delay; 690 responded (83%). Results: Self-reported constipation did not reliably identify functional constipation or outlet delay. The overall age- and gender-adjusted prevalences (per 100) of functional constipation and outlet delay were 19.2 (95% confidence interval [CI], 16.1-22.3) and 11.0 (95% CI, 8.7-13.3), respectively. Outlet delay but not functional constipation was more frequent in women. After adjusting for age, gender, and other symptoms, an increased usage of aspirin was associated with functional constipation but not outlet delay. Conclusions: In apparently healthy middle-aged persons, approximately 1 in 5 have symptoms compatible with functional constipation, and 1 in 10 may experience outlet delay, but these groups correspond poorly with self-reported constipation.