Prevalence and risk factors of constipation among psychiatric outpatients: A cross-sectional study

To determine the prevalence of constipation among psychiatric outpatients and identify associated risk factors.

A cross-sectional survey was conducted at our hospital from February to April 2025. Psychiatric outpatients (N = 2971) were invited to complete an online questionnaire assessing constipation via Rome IV criteria, the Bristol Stool Form Scale (BSFS), and self-reported constipation. Symptom severity and quality of life were measured using the PAC-SYM and PAC-QOL scales. Data analysis included Spearman correlation and multivariate logistic regression.

Among 1045 valid respondents (52.0% effective response rate), constipation prevalence was 21.63% (Rome IV), 34.74% (BSFS), and 29.28% (self-report). For Rome IV-defined constipation, risk factors included history of comorbidity (OR = 1.66; 95% CI: 1.17-2.36), depression disorder (OR = 1.61; 95% CI: 1.17-2.22), and history of lactulose (OR = 2.76; 95% CI: 1.87-4.09) or glycerin enema (OR = 3.04; 95% CI: 1.94-4.76; all P < 0.01). In the Bristol model, risk factors included schizophrenia (OR = 2.12), and history of lactulose (OR = 1.72) or enemas (OR = 1.84). For self-reported constipation, risk factors included female (OR = 1.79), depression disorder (OR = 1.56), and history of lactulose (OR = 3.03) or enemas(OR = 3.73) (all P < 0.01). Constipated patients had higher symptom severity (PAC-SYM: 7.0-11.5 vs. 2.0-3.0) and worse quality of life (PAC-QOL: 19.0-31.0 vs. 11.0-15.0; P < 0.001).

Constipation is prevalent among psychiatric outpatients and is associated with specific demographic and clinical factors. Targeted screening and management focusing on laxative use and psychiatric diagnoses may improve patient outcomes.