What Are FODMAPs?

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FODMAPs is a term used to describe a group of carbohydrates found in common foods that have been identified as possibly exacerbating unwanted digestive symptoms in people who have irritable bowel syndrome (IBS).

What Does FODMAP Stand For?

The term FODMAP is an acronym that was coined by a group of researchers out of Monash University in Australia as a way to refer to these particular carbohydrates.

The term FODMAP gets its letters from:

  • Fermentable
  • Oligosaccharides
  • Disaccharides
  • Monosaccharides
  • Polyols

Looking at FODMAPs more specifically, you may in fact recognize some of them:

The oligosaccharides are comprised of the FODMAP types fructans and galactans.

The disaccharide is the milk sugar lactose.

The monsaccharide is fructose.

The polyols are sugar alcohols such as sorbitol, mannitol, xylitol and maltitol.

What Makes a Carbohydrate a FODMAP?

FODMAPs are substances that are poorly absorbed by the small intestine, which means they become available to be acted upon by bacteria that are within the large intestine. To varying degrees they have the quality of being fermentable, meaning that they interact with gut bacteria in such a way as to increase intestinal gas. In addition, and also to varying degrees, the FODMAPs can be osmotic, meaning that they increase the volume of water in stool. It is thought that this increase in either gas or liquid, or both, contributes to the IBS symptoms of pain, gas and bloating, and constipation and diarrhea.

What Is the Low-FODMAP Diet?

The researchers from Monash University have designed the low-FODMAP diet as a dietary treatment for IBS. The diet requires that you avoid eating any high-FODMAP foods for an elimination phase lasting anywhere from two to eight weeks. At the end of this elimination phase, you would then slowly introduce each FODMAP type back into your diet, one by one, to accurately pinpoint which FODMAPs are a problem for you.


The reintroduction process is extremely important. Not every FODMAP type is a problem for every person who has IBS. In addition, following the full elimination diet for a period of time is thought to improve your tolerance for previously problematic FODMAPs. Once you identify which FODMAPs you can tolerate, and which ones trigger symptoms, you are encouraged to eat as varied a diet as possible given this information.

Research has found that the diet can be very effective when followed under the supervision of a dietitian. In clinical studies, approximately 75% of IBS patients who follow the diet experience significant relief of their IBS symptoms.

The diet is not intended for long-term use. Many high-FODMAP foods are very good for our overall health. Many of them are considered prebiotics, meaning that they enhance a healthy balance of gut bacteria. Thus the reintroduction phase, and continued re-testing of foods in the future, is extremely important so as to ensure that you are eating as varied a diet as you can without re-experiencing symptoms.


Gibson, P. & Shepherd, S. "Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach" Journal of Gastroenterology and Hepatology 2010 25:252-258.

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