Can diet help my IBS?

Diet is a frontline therapy for Irritable Bowel Syndrome (IBS). However, 30% of people with IBS simply DO NOT respond to the most popular dietary intervention – the low fodmap diet. Why? Are they doing something wrong or are there other reasons that explain why a diet low in fodmaps doesn’t work for everyone? Here’s what we’ve pulled out of the literature:

1.     Differences among IBS subtypes (IBS-D prominent diarrhea vs IBS-C prominent constipation) might explain why people respond differently to fermentable carbohydrates. On the whole, people with IBS-D report better outcomes on a low fodmap diet than those with IBS-C.

2.     The low fodmap diet reduces the severity of some gut health symptoms, but not all. If bloating and abdominal pain are not your worst symptoms, you may not see the outstanding benefits that others rave about.

3.     Genetic variances (specifically, a group of surcase-isomaltase gene variants) might explain why some IBS-D patients do not respond as favourably to a low fodmap diet as others. IBS-D patients carrying the SI genes are 3-4 times less likely to benefit from symptom relief when following the diet.

4.     There’s no doubt that following a low fodmap diet can be hard work! Professional support via a dietician or nutritionist in implementing a low fodmap diet achieves better outcomes. But where this isn’t available, accessible or affordable, a diet that reduces gut stimulants (caffeine, alcohol, spicy foods) and modulates meal size and frequency may be just as effective.

5.     The lack of both soluble and insoluble fibre in a low fodmap diet might negate any of its other benefits, especially in IBS-C subtypes.

6.     While many report short term benefits following the elimination phase of the low fodmap diet, there are few double-blinded studies that measure the nutritional and microbiome impacts of the diet over time. The short term benefits may well be short lived and its positive effects may diminish over time.

7.     No ONE single diet can successfully counter the negative and chronic impact of stress, anxiety, substance abuse (alcohol, cigarettes or other), immobility and/or being outside a healthy BMI range.

A diet low in fodmaps is not a magical solution. But… it will help some people with some symptoms some of the time!