What is a Low-FODMAP Diet? And How Can it Help IBS?

What is a Low-FODMAP Diet? And How Can it Help IBS?

IBS - Irritable Bowel Syndrome - is a functional disorder of the gastrointestinal tract and can cause bloating, gas, and diarrhea. It can be frustrating and uncomfortable. 

As we discussed in our last blog, there are a number of general diet and lifestyle tips for people to manage IBS symptoms. However, If symptoms persist, the second-line intervention in IBS dietary management usually includes more advanced dietary changes to hopefully alleviate symptoms. Some people with IBS follow, or get recommended to follow a low-FODMAP diet. 

What are "FODMAPs"?

FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols.

The term FODMAP is used to describe groups of poorly absorbed short-chain fermentable carbohydrates that are naturally present in many foods. These include:

  • Fructans and fructo-oligosaccharides in garlic and wheat
  • Galacto-oligosaccharides in legumes
  • Lactose in dairy products
  • Excess fructose in apples
  • Polyols in stone fruits


When someone has IBS, FODMAPs can pass unabsorbed to the colon - large amounts can lead to increased gas production due to fermentation by the gut microbes living there. Excess production of gas can result in bloating and other GI symptoms in patients with IBS. A low FODMAP diet restricts the dietary intake of these carbohydrates with the overall aim to improve IBS symptoms.

The Low-FODMAP Diet

Foods are classified into “high FODMAP” and “low FODMAP”. The goal of the FODMAP diet is to reduce your intake of high FODMAP foods for a period of weeks to months to see if symptoms of IBS improve. This is then followed by a period of reintroduction of higher FODMAP foods to determine which ones are tolerable.

Relying on a strict low-FODMAP diet is not a good long-term strategy as many of these foods are healthy vegetables and fruits that contain beneficial compounds, and severely restrictive dietary patterns can cause nutrient deficiencies!

Here are some high-FODMAP foods to avoid, and low-FODMAP alternatives to try instead:

High-FODMAP and Low-FODMAP foods and alternatives to help with IBS symptoms - Sperri - Plant-Based Meal Replacement

Two areas of concern when following a low-FODMAP diet can be:

  • Prebiotic fibre intake (these fibres feed your gut microbes)
  • Calcium

In the short term, it is unlikely that this will become a concern, however, long-term removal of major food groups can lead to health issues.

A low FODMAP diet may be very helpful to control IBS symptoms in the short term, however, it can be difficult to do on your own due to the relative complexity of following this pattern compared to more basic strategies. For this reason, and the risk of long-term dietary restriction leading to inadequate nutrition it's best to speak with a healthcare provider and get support from a nutritionist, dietitian, or knowledgeable physician before considering a low-FODMAP diet.

As always, it's important to listen to your body, and do what works for you!