The Low FODMAP Diet for irritable bowel syndrome (IBS)
10-second takeaway: The low FODMAP diet involves the restriction of certain carbohydrates to improve symptoms of irritable bowel syndrome (IBS) and uncover “trigger foods”. It may not be useful or suitable for every patient with IBS but can be useful in other gastrointestinal disorders.
In 2004, Australian researchers at Monash University first established the low FODMAP diet marking a significant milestone in the management of IBS-related symptoms. The low FODMAP diet has since become a widely studied elimination diet, particularly renowned for its effectiveness in managing symptoms associated with irritable bowel syndrome (IBS) and other gastrointestinal (GI) disorders.
What are FODMAPs?
FODMAP is an acronym for Fermentable Oligo-, Di-, Mono-saccharides And Polyols, encompassing specific types of carbohydrates believed to trigger GI symptoms in some people. These short-chain carbohydrates are highly fermentable, undergoing chemical transformations in the GI system and exhibiting poor absorption during digestion.
Upon reaching the colon, bacteria ferment these sugars generating gas and chemicals that can stretch the colon walls, leading to symptoms like abdominal bloating, distension, cramping, pain, and alterations in bowel habits- all especially prevalent among IBS patients. It’s important to note that FODMAPs aren’t inherently harmful but may exacerbate GI symptoms in individuals with sensitive GI tracts.
How does the low FODMAP diet work in practice?
There are three phases in the low FODMAP diet:
- Elimination phase: Lasting 2-4 weeks, all FODMAPs are removed from the diet. If symptoms notably improve during this phase, patients proceed to the next phase
- Reintroduction phase: FODMAP groups are reintroduced one at a time while monitoring for symptom recurrence.
- Personalization phase: Once trigger FODMAPs are identified, patients may avoid these foods while still consuming other FODMAPs to maintain nutritional diversity. Adherence to this personalized low FODMAP plan doesn’t cure IBS, but can effectively manage symptoms and enhance quality of life.
Navigating the extensive list of dietary restrictions and recommendations can be overwhelming for many patients, underscoring the value of guidance from experienced dietitians during the elimination and reintroduction phases.
Eliminating restricting FODMAPs from the diet can significantly alleviate symptoms of IBS and other functional GI diseases, particularly in individuals who perceive a connection between their food intake and GI symptoms. The Low FODMAP diet can be used in isolation or alongside medications for IBS treatment, with improvements commonly observed in bloating, abdominal pain, fatigue, bowel movements, and overall quality of life.
Can the low FODMAP diet work for other GI conditions?
While predominantly studied in the context of IBS, the Low FODMAP diet is increasingly utilized for other GI conditions due to overlapping symptomatology. In cases where symptoms persist, the diet may complement treatment for different conditions including:
- Inflammatory bowel disease (Crohn’s disease and ulcerative colitis)
- Coeliac disease
- Small intestinal bacterial overgrowth
Collaboration with GI healthcare providers and dietitians specializing in GI conditions enhances the likelihood of success with this elimination diet strategy. However, it’s important to recognize that the low FODMAP diet may not be suitable for everyone, particularly individuals with a history of eating disorders and those with complex medical histories.
Key takeaways
- The low FODMAP diet can help patients with IBS to alleviate their GI symptoms and identify specific foods that trigger these symptoms
- FODMAPs are not inherently bad and will not cause symptoms in every patient, so it is important to support patients looking to make dietary changes for the benefit of their health
- The low FODMAP diet can be very restrictive so it may not be suitable for all patients and, ideally, should not be used long-term
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About the author
Julia Mor is a nutritionist working in healthcare and currently diving deep into the world of nutrition and behaviour with an MSC at Bournemouth University. She has a soft spot for exploring how gut health ties into our mental well-being and a particular interest in inflammatory bowel disease (IBD)
Reference list
- Bellini, M., Tonarelli, S., Nagy, A. G., Pancetti, A., Costa, F., Ricchiuti, A., de Bortoli, N., Mosca, M., Marchi, S. and Rossi, A., 2020. Low FODMAP Diet: Evidence, Doubts, and Hopes. Nutrients [online], 12 (1), 148. Available from: https://www.mdpi.com/2072-6643/12/1/148.
- Eswaran, S., 2021. Low-FODMAP Diet [online]. American College of Gastroenterology. Available from: https://gi.org/topics/low-fodmap-diet/.
- Gibson, P. R., 2017. History of the low FODMAP diet. Journal of Gastroenterology and Hepatology, 32 (S1), 5–7. https://doi.org/10.1111/jgh.13685
- Harvard Health Publishing, 2014. Try a FODMAPs diet to manage irritable bowel syndrome [online]. Harvard Health. Available from: https://www.health.harvard.edu/diseases-and-conditions/a-new-diet-to-manage-irritable-bowel-syndrome.
- LDN, E. G., MLA, RD, 2020. The lowdown on the low-FODMAP diet [online]. Harvard Health Blog. Available from: https://www.health.harvard.edu/blog/the-lowdown-on-the-low-fodmap-diet-2020072720662.
- Monash University, 2019. Low FODMAP Diet | IBS Research at Monash University
- van Lanen, A.-S., de Bree, A. and Greyling, A., 2021. Efficacy of a low-FODMAP diet in adult irritable bowel syndrome: a systematic review and meta-analysis. European Journal of Nutrition [online], 60 (6). Available from: https://pubmed.ncbi.nlm.nih.gov/33585949/.
