Low frequency of defecation and hard stool are not reliable indicators of constipation in Chinese population

Abstract

Background: This study investigated the prevalence, characteristic symptoms and risk factors of constipation in the Chinese population. Methods: Data of 3450 respondents from the general Chinese population who completed the digital Groningen Defecation and Fecal Continence (DeFeC) questionnaire were analyzed. The non-comorbidity subgroup was defined as respondents without organic comorbidities known to influence defecation. Constipation and dyssynergic defecation prevalence and severity were evaluated using Rome IV criteria and the Renzi score (Obstruction Defecation Syndrome Score), respectively. A logistic regression analysis was used to identify factors contributing to constipation. Results: The prevalence of constipation was 20.4% in the total group and 18.7% in the non-comorbidity subgroup (n = 3145). Among the constipated non-comorbidity subgroup respondents, the median and interquartile range of Renzi score was 6 (5–8). The following symptoms related to dyssynergic defecation had the highest prevalence: straining during defecation, 86.4%; incomplete defecation, 75.1%; feeling of blockage, 63.4%; and anal pain, 46%. Women were more prone to constipation than men (odds ratio [OR], 1.87; 95% confidence interval [CI], 1.53–2.28). Additionally, obese respondents (OR, 1.36; 95% CI,1–1.87), those who ate spicy food four to five times per week (OR, 5.33; 95% CI, 3.61–7.89), and those living in a metropolitan city (OR, 1.34; 95% CI, 1.08–1.68) were more prone to constipation. Conclusion: The Chinese population has a high prevalence of constipation. A significant proportion of constipated respondents reported symptoms typical for dyssynergic defecation. The low defecation frequency and hard stool seem not to be reliable indicators of constipation.