Charting a Course to a Less Restrictive Diet for IBS

Irritable bowel syndrome (IBS) is the most common gastrointestinal disease, affecting 12% of the US population and up to 20% of the population worldwide. This is a condition that is diagnosed based on specific symptoms of altered bowel habits and abdominal pain, as well as the exclusion of select other GI diseases. IBS not only causes constipation, diarrhea, abdominal cramping, and bloating, it also significantly affects quality of life, overall functioning, and work productivity.

The cause of IBS is likely multifactorial, which makes it a difficult disease to treat. However, patients often associate their IBS symptoms with eating a meal. Up to 90% of IBS patients restrict their diet to prevent or improve their symptoms, and patients are increasingly interested in more holistic approaches to disease management. At present, the most persuasive evidence that dietary changes can treat IBS supports a diet low in fermentable carbohydrates (the low FODMAP (fermentable oligo, di, and monosaccharides and polyols) diet). This diet, which is low in certain carbohydrates, has been shown to improve IBS symptoms (particularly abdominal pain and bloating), but can be difficult to follow and quite restrictive. In addition, this diet is not meant to be used as a maintenance diet; patients undergo an elimination phase followed by a reintroduction phase of specific carbohydrate groups as they monitor their symptoms. From the results of our proposed study, the study team hopes to arrive at a modified, less -restrictive version of the low FODMAP diet that is equally effective, and also create a standard protocol that patients can use during this reintroduction phase.

Patients with IBS will be recruited into a 13-week trial that would help determine the optimal way in which high FODMAP foods should be introduced. After consent, patients would start on a low FODMAP diet for 14 days, and if their symptoms improve, they would be invited to continue in the study. For 7 days prior to the reintroduction of individual FODMAPs, patients will ingest 1daily servings of a low FODMAP nutrition drink to validate the low FODMAP content of this dietary supplement. If patients do not experience a flare of symptoms with the supplement, they enter the reintroduction period. During this period, subjects would introduce different groups of FODMAPs in a blinded fashion while remaining on an otherwise low FODMAP diet while monitoring their IBS symptoms. At the end of the study period, subjects would be informed of the FODMAPs to which they were sensitive and would meet with a dietitian. At the completion of the study, the investigators would compile the data and determine which FODMAPs were mostly likely to exacerbate IBS symptoms, thus providing the construct for a modified low FODMAP diet, or "low FODMAP-Light." It is hoped that this modified, less restrictive version of the low FODMAP diet would be equally effective for the majority of IBS patients.