What is the low FODMAP diet?

The low FODMAP diet is the most effective dietary strategy that currently exists for the management of IBS (irritable bowel syndrome). It’s such a horribly un-sexy, hard to market name that you know it’s got to be pretty legit! It’s actually thought to improve symptoms in 70% of patients diagnosed with IBS (1).

The low FODMAP diet works by reducing a person’s intake of FODMAPs, which are Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols. In other words, FODMAPs are fermentable carbohydrates. These carbohydrates are not fully digested or absorbed in the small intestine, which means that they make their way to the large intestine where they serve as a food source for all of the bacteria that live there.

Bacteria ferment the carbohydrates that reach the large intestine, breaking down the carbohydrates and releasing gas as a result. This is a normal part of digestion, and it happens to all of us. Feeding these bacteria is important for our gut health. But for some people (not all people), it is thought that this gas production contributes to their IBS symptoms, which can include lower abdominal pain, bloating, excessive passage of wind, distension, diarrhoea and/or constipation, depending on the person. Some unlucky people will experience all of these symptoms, sometimes many of them at once!

To find out whether you are one of the 70% of IBS sufferers who will benefit from a low FODMAP diet you need to commence an elimination diet, which should be followed for between 2 and 6 weeks. If symptoms resolve during this time, you need to gradually reintroduce FODMAPs one a time to establish which particular carbohydrates are a problem for you. Most people who benefit from the diet are not sensitive to all FODMAPs, maybe just one or two categories.

It’s important not to follow the elimination diet long term, as current research suggests that this will cause negative changes to the beneficial bacteria that live in your gut. A dietitian with experience in the low FODMAP diet can guide you through the elimination diet and the reintroduction phase, ensuring you are doing so in the healthiest way possible.

Want to figure out if FODMAPs are contributing your IBS symptoms? Click here to request an appointment with me in person at the Brisbane clinic or via Skype, or click here to read more about the services I offer.


  1. Gibson, P. (2017). The evidence base for efficacy of the low FODMAP diet in irritable bowel syndrome: is it ready for prime time as a first-line therapy? Journal of Gastroenterology & Hepatology. [Article Link]

Ashleigh Jones

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