Diet in subjects with irritable bowel syndrome: A cross-sectional study in the general population

Background: Patients with irritable bowel syndrome (IBS) often relate symptoms to the intake of certain foods. This study assesses differences in diet in subjects with and without IBS. Methods: The cross-sectional, population-based study was conducted in Norway in 2001. Out of 11078 invited subjects, 4621 completed a survey about abdominal complaints and intake of common food items. IBS and IBS subgroups were classified according to Rome II criteria. Results: IBS was diagnosed in 388 subjects (8.4%) and, of these, 26.5% had constipation-predominant IBS (C-IBS), 44.8% alternating IBS (A-IBS), and 28.6% diarrhoea-predominant IBS (D-IBS). Low intake of dairy products (portions/day) (Odds Ratio 0.85 [CI 0.78 to 0.93], p = 0.001) and high intake of water (100 ml/day) (1.08 [1.02 to 1.15], p = 0.002), tea (1.05 [1.01 to 1.10], p = 0.019) and carbonated beverages (1.07 [1.01 to 1.14], p = 0.023) were associated with IBS. A lower intake of dairy products and a higher intake of alcohol and carbonated beverages were associated with D-IBS and a higher intake of water and tea was associated with A-IBS. In subjects with IBS the severity of symptoms was associated with a higher intake of vegetables and potatoes in subjects with C-IBS, with a higher intake of vegetables in subjects with A-IBS, and with a higher intake of fruits and berries, carbonated beverages and alcohol in subjects with D-IBS. Conclusions: In this study, the diet differed in subjects with and without IBS and between IBS subgroups and was associated with the severity of symptoms.