AGA issues best practice advice on IBS and diet

Dietary advice is ideally prescribed to patients with irritable bowel syndrome (IBS) who have insight into their meal-related GI symptoms and are motivated to make changes, the American Gastroenterological Association (AGA) said.

Patients with irritable bowel syndrome (IBS) who have insight into their meal-related GI symptoms and are motivated to make necessary changes are the best candidates for dietary advice, according to a new clinical practice update from the American Gastroenterological Association on IBS and diet.

The update consists of best practice advice statements developed on the basis of a review of existing literature and expert opinion, with the goal of providing practical advice on the role of diet in treating IBS. The statements were not rated for quality or strength of evidence because they were not based on a systematic review. The clinical practice update was published March 23 by Gastroenterology.

To optimize dietary advice, patients willing to collaborate with a registered dietitian nutritionist (RDN) and those who are not able to make beneficial dietary changes on their own should be referred for consultation, the update said. Other resources can be used to assist with implementation of dietary interventions if an RDN is not available.

Other best practice advice included the following:

  • Patients with IBS who consume few culprit foods, are at risk for malnutrition, are food insecure, or have an eating disorder or uncontrolled psychiatric disorder are poor candidates for restrictive diet interventions. Routine screening for disordered eating or eating disorders by careful dietary history is critical, since they are common and often overlooked in GI conditions.
  • Specific diet interventions should be attempted for a predetermined length of time and should be discontinued for another treatment (e.g., a different diet or medication) if there is no clinical response.
  • Before an RDN visit, patients should provide dietary information to help inform development of an individualized nutrition care plan.
  • Soluble fiber is efficacious in treating global IBS symptoms.
  • A diet low in fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) is currently the most evidence-based diet intervention for IBS. Healthy eating advice as described by the National Institute of Health and Care Excellence guidelines, among others, can also benefit a subset of IBS patients.
  • The three phases of the low-FODMAP diet are restriction (lasting no more than four to six weeks), reintroduction of FODMAP foods, and personalization based on results from food reintroduction.
  • Observational studies have found that IBS improves in most cases with a gluten-free diet, but results from randomized controlled trials have been mixed.
  • While some data show that selected biomarkers can predict response to diet interventions in IBS, evidence to support their routine use in clinical practice is insufficient.