Key takeaways
- FODMAPs are fermentable carbohydrates that can trigger symptoms in some people with IBS.
- The low-FODMAP diet is meant to be temporary and ideally guided by a dietitian.
- A 'low-FODMAP' fiber is useful if you are sensitive to inulin-type fibers.
- If you have no symptoms, there is usually no reason to restrict FODMAPs.
FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols. These are short-chain carbohydrates found in foods such as onions, garlic, wheat, some fruits and many sweeteners. They draw water into the gut and ferment quickly, which can cause gas, bloating and pain in people with irritable bowel syndrome (IBS).
Where the diet comes from
The low-FODMAP diet was developed by researchers at Monash University in Australia. It is not a lifelong plan. It has three phases: a short elimination period, a structured reintroduction to find out which FODMAPs cause trouble, and a personalized long-term diet that restricts as little as possible. A registered dietitian can guide this.
Why fiber needs a second look
Many 'gut health' products contain inulin, chicory root or fructooligosaccharides (FOS). These are prebiotic fibers, and they are also high in FODMAPs. For someone who is sensitive, they can make symptoms worse even though they are marketed as helpful.
Fibers often tolerated by people who are FODMAP-sensitive
- Psyllium husk: a soluble fiber that is generally well tolerated and has been studied in IBS.
- Partially hydrolyzed guar gum: studied in IBS and often listed as better tolerated than inulin.
- Oats, chia and flax: everyday foods that provide fiber in moderate portions.
Individual tolerance varies, so portion size and trial and error matter. The Monash app and website maintain up-to-date food lists.
Who this is not for
If you have no digestive symptoms, cutting FODMAPs is unnecessary. Some studies suggest long-term restriction can reduce the variety of foods and beneficial bacteria in the gut, which is the opposite of what most people want.
See a professional if
- You have not been diagnosed and your symptoms are new, severe or getting worse.
- You have weight loss, night symptoms, fever or blood in your stool.
- You are thinking of cutting out several food groups at once.
Sources and further reading
- Monash University FODMAP Diet
- NIH National Center for Complementary and Integrative Health
- MedlinePlus (U.S. National Library of Medicine)
General reference sources, linked for further reading. Always check current guidance for your country and situation.
Reviewed and updated October 17, 2026. This article is for general information and is not medical advice. See our medical disclaimer.
