Background: Childhood constipation is prevalent and negatively affects quality of life. Although psychological stress and family environment have been identified as risk factors, few epidemiological studies have examined this issue. We aimed to clarify associations of psychological stress and family environment with childhood constipation in a large-scale epidemiological study.

Methods: In total, 7,998 children aged 9–10 years from the Toyama Birth Cohort Study completed questionnaires. Constipation was defined as bowel movements “less frequently than once every 2 days”. Children’s lifestyles, including food frequency, psychological stress, family environment, frequency of irritability, unwillingness to attend school, and frequency of interaction with their parents, were analyzed via multivariate logistic regression analysis. Parental employment status and presence at dinner were also examined.

Results: In total, 312 children (3.9%) experienced constipation. Girls were more likely to experience constipation than boys (5.1% vs 2.8%). In addition, constipation was significantly associated with girl (odds ratio [OR] 1.97; 95% confidence interval [CI], 1.55–2.51), physical inactivity (OR 1.41; 95% CI, 1.01–1.95), overweight (OR 0.58; 95% CI, 0.40–0.85), infrequent fruit (OR 1.94; 95% CI, 1.42–2.66) and vegetable (OR 1.46; 95% CI, 1.03–2.05) consumption, frequent irritability (OR 1.76; 95% CI, 1.24–2.50), unwillingness to attend school (OR 1.66; 95% CI, 1.13–2.43), and infrequent interaction with parents (OR 1.48; 95% CI, 1.06–2.07). Children whose parents were absent at dinner were more likely to experience constipation compared to those whose parents were present at dinner; however, this differences were not statistically significant.

Conclusion: Psychological stress and infrequent interaction with parents were as strongly associated with childhood constipation as conventional risk factors. Psychological stress and family environment should be more prioritized in caring childhood constipation.