What are FODMAPs?

FODMAP is an acronym created by researchers at Monash University in Australia. It stands for a group of fermentable carbohydrates (sugars and fibers) that can be difficult for some people to digest. These sugars can trigger digestive symptoms like bloating, gas, diarrhoea, constipation, and abdominal pain—all very common in IBS.

Here’s what each letter stands for:

F – Fermentable

This refers to the process where gut bacteria break down undigested carbohydrates, producing gases like hydrogen, methane, and carbon dioxide (2 3 4). For people with IBS, this gas can cause uncomfortable symptoms.

O – Oligosaccharides

There are two types of these:

• Fructans – found in foods like onions, garlic, wheat, and rye.
• Galacto-oligosaccharides (GOS) – found in foods like chickpeas, almonds, silken tofu and soy milk.

Fun fact: Humans actually lack the enzymes to break these down, which is why they often cause gas and bloating—yes, that’s why beans have the reputation they do!

(2 3 4)

D – Disaccharides

The main one here is lactose, the sugar found in dairy products like milk, yoghurt, cream, soft cheeses, and ice cream. To digest lactose, your body needs an enzyme called lactase. If you don’t produce enough, you may experience symptoms like bloating, gas, and diarrhoea after eating dairy.

But don’t worry—there are plenty of low-lactose or lactose-free options available.

(2 3 4)

M – Monosaccharides

This refers to fructose, a natural sugar found in certain fruits, vegetables, and sweeteners like mango, asparagus, apples, pears, honey and high fructose corn syrup.

Fructose only becomes an issue when there is more fructose than glucose in the food (glucose helps your body absorb the fructose). For some people, the excess fructose can trigger unpleasant gut symptoms when it is malasorbed in the intestines (2 3 4).

While on the low FODMAP diet, you’ll focus on eating foods that have a balanced fructose to glucose ratio and avoid serving sizes of foods that contain excess fructose.

A and P – And Polyols

Polyols are sugar alcohols, found both naturally in some fruits and vegetables (think mushrooms, celery, watermelon) and in many sugar-free gums, mints, and sweeteners. Examples include sorbitol, mannitol, xylitol, and maltitol.

Even though they’re called “alcohols,” they don’t contain any booze—just a chemical structure that makes them poorly absorbed in your gut.

(2, 4)

Why try the low FODMAP diet?

If you’re living with IBS, you’re probably all too familiar with the unpredictable and unpleasant symptoms, discomfort, and frustration that come with managing gut issues. The low FODMAP diet has been shown in research to improve symptoms in up to 75% of people with IBS (4).

It works by temporarily reducing the amount of FODMAPs in your diet, allowing your gut to settle. Over time, you’ll work with a dietitian to reintroduce different foods to find your personal triggers.

⚠️ Important: This is a medical diet, not a long-term lifestyle change. Please consult with your doctor first, and ideally work with a registered dietitian who can guide you through the different phases while keeping your diet healthy and balanced.

If you are unable to work with a dietitian then we can guide you through the diet in our FODMAP Made Easy program.

How do FODMAPs trigger IBS symptoms?

Here’s what happens in simple terms:

1. 1. 1. Malabsorption – Your small intestine struggles to absorb certain FODMAPs.
      2. Water retention – This draws water into your small intestine, potentially leading to diarrhoea.
      3. Fermentation – The leftover sugars (FODMAPs) travel to your large intestine, where they become fast food for your gut bacteria. As the bacteria break down the FODMAPs the fermentation process creates gas, which can lead to bloating, cramping, and excess wind and altered bowel movements.
      4. Distension – The combination of gas and water stretches your gut, activating nerves and causing pain or a feeling of fullness.

      (5, 1)

Examples of High and Low FODMAP Foods

Learning which foods are high or low in FODMAPs is key to calming your gut. Below is a simple chart to get you started:

For an extensive and up-to-date list of high and low FODMAP foods please get the Monash University FODMAP Diet App.

Table of FODMAP Foods

(Table Sourced from: 2, 4)

👉 For a full list of foods, download the Monash University Low FODMAP app, which is regularly updated with new food tests.

Next steps before you start

Before you start the low FODMAP diet there are a few things you need to do:

• Check with your doctor that the diet is right for you.
• Ask for a referral to a dietitian who is trained in the low FODMAP diet
• Read our guide on how to start the low FODMAP diet.
• Understand how the FODMAP reintroduction phase works.
• Sign up to the FODMAP Made Easy program so we can quickly guide you through the low FODMAP diet without food fear and confusion.

Final Thoughts

Getting started with the low FODMAP diet can feel a bit overwhelming—but remember, you’re not in this alone. With the right support and information, many people with IBS find real relief by identifying their trigger foods and building a long term diet that works for them.

Small changes can make a big difference to your gut—and your quality of life.

References

1. BPACnz. Irritable bowel syndrome in adults: Not just a gut feeling. Best Practice Journal. 2014: Issue 58. 14-25. Retrieved from http://www.bpac.org.nz/BPJ/2014/February/ibs.aspx

2. Monash University FODMAP Diet App. Food Guide. The Monash University FODMAP Diet App. 2025: Version 3.1.5. Date retrieved: 2025-04-29. Retrieved from :https://www.monashfodmap.com/ibs-central/i-have-ibs/get-the-app/. Accessed: 2025-04-29

3. Mansueto, P., Seidita, A., D’Alcamo, A., Carroccio, A. Role of FODMAPs in Patients with Irritable Bowel Syndrome: A Review. Nutrition in Clinical Practice Journal. 2015-02-18. DOI: 10.1177/0884533615569886. Retrieved from http://ncp.sagepub.com/content/early/2015/02/17/0884533615569886

4. Monash University. Frequently Asked Questions Section. Monash University. 2015b. Retrieved from https://www.monashfodmap.com/about-fodmap-and-ibs/ Retrieved on 2025-04-29.

5. Central Clinical School, Monash University. The FODMAP Grand Tour Down Under: IBS relief. 2019. Retrieved from: https://www.youtube.com/watch?v=Z_1Hzl9o5ic