RESUMO
BACKGROUND AND OBJECTIVE: A low FODMAP diet (LFD) has become a standard treatment in irritable bowel syndrome (IBS) patients. Compliant adherence to a LFD is challenging. We investigated the effect of a LFD compared to a less restrictive low lactose diet (LLD) in a randomized cross-over trial with IBS patients. METHODS: Twenty-nine IBS patients were randomly assigned to two groups. After a run-in phase of 14 days, patients received 21 days of either a LFD or LLD. This intervention was followed by a washout period of 21 days before crossing over to the alternate diet. Dietician led diet instruction was given continuously. An IBS Severity Scoring System (IBS-SSS) was filled in at the end of each study period. To enhance study adherence, daily symptoms were assessed using a Visual Analog Scale (VAS). RESULTS: IBS patients, irrespective of lactase deficiency, had a significantly reduced IBS-SSS score after both diets (LFD p = 0.002, LLD p = 0.007) without significant difference. On both diets, patients reported that IBS had less impact on their daily life compared to the time before the study (p < 0.01). On daily assessment, IBS patients on LFD reported significantly less abdominal pain (median VAS difference to baseline -0.8 (-2.8 to 2.7, p = 0.03) and less bloating (-0.5 (-4.1 to 3.4, p = 0.02) than patients on the LLD. CONCLUSION: Both diets improved the overall IBS severity significantly and patients' preference of the two diets was similar. LFD but not LLD effectively reduced pain and bloating in patients with IBS.