Prevalence and Self-recognition of Chronic Constipation: Results of an Internet Survey

BACKGROUND/AIMS: Although chronic constipation is a common symptom, to date no international consensus has been reached regarding its definition. The aims of this study were (1) to investigate defecation habits and (2) to examine the prevalence of constipation using the Japanese Society of Internal Medicine (JSIM) and the Rome III criteria using an online survey. METHODS: An online questionnaire composed of items on the frequency, interval, form of defecation, the management, and self-recognition of constipation (reference standard of constipation) was created. A total of 5155 valid responses were received. In addition, constipation symptoms were evaluated through a survey using the JSIM and the Rome III criteria. RESULTS: In the internet survey, 28.4% of the respondents considered themselves to be constipated. Stratified by sex, significantly more females (37.5%) than males (19.1%) considered themselves to be constipated (P < 0.001). The prevalence of constipation among the respondents was 28.0% using the Rome III, but only 10.1% using the JSIM. The diagnostic accuracy was 73.2% for the Rome III and 78.1% for the JSIM, while the diagnostic specificity was 81.1% for the Rome III and 97.5% for the JSIM. However, the diagnostic sensitivities for both measures were low, at 52.2% and 29.2% for the Rome III and the JSIM, respectively. CONCLUSIONS: The online survey developed for this study was able to provide clarification regarding defecation patterns. The results also suggest a discrepancy between the self-recognized prevalence of constipation in Japan and prevalence of constipation based on the JSIM criteria.