According to recent estimates, IBS affects approximately 11% of people globally, with the disorder occurring more frequently in women and young adults than in other patient groups. A diagnosis of IBS is made based on a clinical evaluation of symptoms. Using the Roma III criteria, patients with IBS are classified into one of four subtype categories according to their predominant gastrointestinal (GI) symptoms:

  • IBS with predominant constipation (IBS-C)
  • IBS with predominant diarrhea (IBS-D)
  • IBS with a mix of irregular bowel habits (IBS-M)
  • IBS unclassified (IBS-U)

Certain Foods Commonly Avoided in IBS

Various dietary strategies have emerged as effective methods for managing symptoms that contribute to IBS, including low-fat, lactose-free, and gluten-free diets, among others. Over the past decade, gluten-free diets have increasingly gained acceptance among clinicians and patients as a means for improving GI symptoms. “In published research, gluten has been shown to cause adverse reactions among people with IBS,” says Anouk Reuzé, PhD candidate. However, some clinicians tend to recommend a low-FODMAP (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols) diet over a gluten-free diet, whereas patients with IBS have a greater interest in following a gluten-free diet.

Gluten avoidance may be beneficial for a subset of patients with IBS. To look at this issue more closely, Reuzé and a team of French investigators conducted a study, published in Nutrients, to describe self-reported practices of total or partial gluten avoidance in adults with and without IBS. The study included data on more than 15,000 people participating in the nutrient-Santé study who completed a functional GI disorder questionnaire based on Rome III criteria to identify IBS in 2013 and then a food avoidance questionnaire in 2016. About three-quarters of participants (73.4%) were women, and the average age of the total population was 55.8. Of the total study cohort, 804 participants (5.4%) were identified as IBS cases.

Gluten Avoidance Common in IBS to Reduce GI Symptoms

The prevalence of gluten avoidance was higher in patients with IBS than in their non-IBS counterparts for total and partial avoidance, according to the study results. The estimated prevalence of gluten avoidance in people with IBS was 14.8%, compared with an 8.8% rate in those without the disorder. Of note, 3.0% of patients who avoided gluten reported that they eliminated it from their diet entirely (Table). “Our study found that gluten avoidance appears to be consciously followed by many patients with IBS as part of a higher overall dietary management strategy,” says Reuzé. After characterizing patients with IBS by subtype, gluten avoidance was more prevalent among those with IBS-D and IBS-M than for participants with IBS-C or IBS-U.

Additionally, the study demonstrated that patients with IBS did not have low intakes of key nutrients, even in those reporting that they avoided different types of food. However, gluten-free diets still come with nutritional risks that have been seen with other restrictive diets, such as higher food costs and a lack of readily available food options. The authors noted that additional research is needed to investigate the potential long-term impact of gluten-free, ultra-processed foods in IBS.

Taking a Personalized Approach to Manage Patients

Considering that IBS continues to be underdiagnosed or misdiagnosed, clinicians are urged to collaborate with patients to determine if they are adopting self-implemented behaviors—including a gluten-free diet—to alleviate their symptoms. “While there has been some skepticism about the role of a gluten-free diet in IBS, research suggests people who adopt these diets are very adherent to them,” Reuzé says. If patients still suffer from IBS symptoms despite adhering to gluten-free diets, they might be more open to trying the low FODMAP diet as a subsequent option.

The study team emphasizes the importance of personalizing dietary follow-up with patients when managing IBS. “Current guidelines recommend having a qualified dietitian supervise any diets used by patients to ensure they have a personalized dietary framework,” says Reuzé. This is particularly relevant considering the increasing availability of processed gluten-free foods throughout the world.