American Gastroenterological Association Updates Diet Recommendations for Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) can be managed with a variety of treatments but commonly with diet and medications. This document from the American Gastroenterological Association provides “best practice advice” for using diet therapy for IBS. Below are some key points from the clinical practice update:

• Diet advice is best when patients with IBS have insight into meal-related symptoms and are motivated to try changes. If patients are willing, refer them to a registered dietitian nutritionist (RDN).
• Poor candidates for restrictive diets include those consuming few culprit foods or those with malnutrition risk, food insecurity, an eating disorder, or uncontrolled psychiatric disorder. Routine screening for eating disorders is needed because they are common and often overlooked.
• Try a diet change for a specific duration of time and, if there is no response, move on to a different diet change or different therapy. 
• When referring to an RDN, the patient should keep a food diary for at least 3 days with symptom correlation. Insurance payment for the RDN can be a problem; therefore, it is important to document the medical necessity of a consultation and use a specific ICD-10 code.
• Soluble fiber treats global IBS symptoms. Insoluble fiber (wheat bran, whole grains, fruit and vegetable skins, and seeds) does not.
• A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is the best evidence-based diet for IBS. Healthy eating advice (traditional healthy eating as advised in the National Institute for Health and Care Excellence guidelines) is also effective.  
• The restrictive phase of a low-FODMAP diet should last no more than 4 to 6 weeks. This is followed by the reintroduction of FODMAP foods and personalization based on reintroduction results.
• A gluten-free diet is often effective, although randomized controlled trials have had mixed results.