Fermentable Carbohydrate Restriction (Low FODMAP Diet) in Clinical Practice Improves Functional Gastrointestinal Symptoms in Patients with Inflammatory Bowel Disease

Background: A significant proportion of patients with inflammatory bowel disease (IBD) experience functional-like gastrointestinal symptoms (FGS) even during remission. Research suggests that dietary restriction of fermentable carbohydrates (low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet) can improve FGS, albeit in irritable bowel syndrome. The aim of this study was to investigate the effectiveness of the low FODMAP diet delivered in routine clinical practice in patients with IBD and coexisting FGS. Methods: Gastrointestinal symptom scores were compared in consecutive patients with IBD referred for low FODMAP dietary education for symptom management (n = 88). Symptoms were assessed using the Gastrointestinal Symptoms Rating Scale, and stool output was assessed using the Bristol Stool Form Scale at both baseline and follow-up (minimum of 6 weeks). Results: There was a significant and large increase in the numbers of patients reporting satisfactory relief of symptoms between baseline (14/88, 16%) and low FODMAP diet (69/88, 78%; P < 0.001). Following dietary intervention, there was also a significant decrease in severity for most symptoms and a reduction in composite symptom score (baseline mean: 1.2, SD: 0.5 versus low FODMAP diet mean: 0.7, SD: 0.5; P < 0.001). Improvements in stool consistency and frequency were observed, including an increase in "normal" stool form (P = 0.002) and "normal" stool frequency (P < 0.001). Conclusions: The low FODMAP diet delivered in routine clinical practice seems effective in improving satisfaction with, and severity of, FGS in IBD. Randomized controlled trials are warranted to definitively establish effectiveness.