Mental, physical, dietary, and nutritional effects on irritable bowel syndrome in young Japanese women.

OBJECTIVE Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. The pathogenesis of IBS is multifactorial. The aim of this study was to investigate the prevalence of IBS using the Rome III criteria in young Japanese women and to assess the effects of mental, physical, dietary and nutritional factors on IBS. METHODS In this cross-sectional study, data obtained from self-administered questionnaires, including age, height, weight, lifestyle, food habits, anxiety and depressive states and IBS-related symptoms, were analyzed in 245 participants. An established semiquantitative questionnaire available for clinical investigation (FFQg) was used to obtain a detailed assessment of food intake and the physical activity levels. RESULTS The prevalence of IBS was 12.0%. Of the IBS participants, constipation-predominant IBS (25.0%) was more prevalent than the diarrhea-predominant subtype (17.9%). The IBS participants had lower body mass indices, consumed less eggs and milk and were more physically active than the non-IBS participants. In addition, an anxiety state was more common in the IBS participants. Those who hesitated with evacuation of stool and who thought that there is an association between abdominal symptoms, such as constipation and diarrhea, and menstruation were more predominant among the IBS participants. The percentage of individuals who reported often rushing to the toilet within the past year and experiencing borborygmus (rumbling stomach) was greater among the IBS participants. A logistic regression analysis revealed that milk intake was an independent predictor of IBS. CONCLUSION The prevalence of IBS observed in this study was similar to that reported in previous studies conducted in Japan and other countries. Mental, physical, dietary and nutritional factors have an impact on IBS.