How to Relieve IBS with a Low FODMAP Diet

People with irritable bowel syndrome(IBS) frequently suffer severe abdominal pain, bloating and flatulence, along with diarrhea or constipation, or occasionally alternating bouts of both. The situation is frustrating, because they are often told that there is nothing wrong with them; they have a “functional” gastrointestinal disorder. There is hope for easing the symptoms, however. Increasingly, research shows that a low FODMAP diet can be helpful.

What Is a Low FODMAP Diet?

FODMAP stands for fermentable oligo-, di- monosaccharides and polyols. These include compounds such as lactose (milk sugar), fructose, fructans, galactans and “polyols,” also known as sugar alcohols even though you could not get tipsy on them. These compounds are utilized by gut microbes that create gas, which may well be the source of some of the uncomfortable symptoms associated with IBS.

Controlled Trial of a Low FODMAP Diet:

A new study shows that avoiding foods that can be readily fermented by gut bacteria makes a significant difference. More than 90 IBS patients were randomly assigned to follow either a low FODMAP diet or a “sensible diet” that reduced caffeine and alcohol for six weeks. The ones assigned to reducing FODMAP consumption consulted with registered dietitians trained to help people discover which foods they should avoid and make sure the diets they followed as a result did not produce serious nutritional deficiencies. (This is a risk with a severely restricted diet.)

More than 50 percent of those on the low FODMAP regimen reported major improvement in their abdominal pain, compared to 20 percent of those eating sensibly.

Digestive Disease Week, May 24, 2016

Other Studies of IBS Symptoms:

This study is said to be the largest one in the US showing that a low FODMAP diet can ease IBS symptoms. It is not the first in the world, however. Over the past few years there have been a number of studies showing benefit for symptoms such as bloating, gas or discomfort. The first was an Australian pilot study in 2007 (Inflammatory Bowel Diseases, Dec., 2007). By 2010, Australian gastroenterologists concluded, “The low FODMAP diet provides an effective approach to the management of patients with functional gut symptoms. The evidence base is now sufficiently strong to recommend its widespread application.” (Journal of Gastroenterology and Hepatology, Feb., 2010). American doctors did not immediately adopt this approach, however.

In Europe and the UK, a low FODMAP diet is now being recommended for people with irritable bowel symptoms (F1000Research, April 29, 2016; World Journal of Gastroenterology, April 21, 2016). Canadian researchers, among others, have reported that changing the FODMAP content of the diet can alter the ecological balance of the microbes in the digestive tract (Gut, online March 14, 2016). They found that metabolic profiles and immune system reactivity (measured by histamine release) were altered by the low FODMAP diet.

The Take-Away:

It appears that people with IBS could benefit from a referral to a qualified dietitian who can help them map out a low FODMAP diet that is nutritionally balanced for long-term control of symptoms. Some of the restricted foods are those that are generally recommended as healthful, such as legumes, garlic, onions, leeks, mushrooms and many fruits and vegetables. That’s why it is important not to undertake such a restriction long term without guidance.

We spoke with experts about how to alter gut bacteria to reduce reflux and improve digestion (Show 1023). The diet described by Norman Robillard, PhD, has much in common with a low FODMAP diet.