Dietary fiber and risk of irritable bowel syndrome: a case-control study.

AIM: The purpose of this study was to determine the relationship between dietary fiber intake and risk of irritable bowel syndrome (IBS). BACKGROUND: Patients with IBS are usually concerned about their diet, which can exacerbate or relieve their symptoms. METHODS: In this case-control study, ninety cases and 355 controls were selected from a gastroenterology clinic. Dietary intakes of participants were assessed using a validated and reliable food frequency questionnaire (FFQ). Dietary fiber was calculated according to United States Department of Agriculture (USDA) food composition table. RESULTS: Dietary total fiber intake was significantly associated with lower risk of IBS. The adjusted odds ratio (OR) comparing the highest tertile of dietary total fiber with the lowest tertile was 0.14 (95% CI = 0.71-0.28; P-test for trend <0.001); however, there was no significant association or dose-response trend for higher intakes of soluble, and insoluble fiber separately with risk of IBS. CONCLUSION: Our data indicate that dietary fiber is inversely associated with the risk of IBS. Further prospective studies are needed to confirm these data.