FODMAP

FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols, a collection of short-chain carbohydrates and polyols that are poorly absorbed in the small intestine. Because of inadequate absorption, they can draw water into the gut and be rapidly fermented by colonic bacteria, producing gas and luminal distension that may trigger symptoms in some people.

The FODMAP family includes several subgroups: oligosaccharides such as fructans and galacto-oligosaccharides; disaccharides such as lactose; monosaccharides such as excess fructose relative to glucose; and polyols such as sorbitol, mannitol, xylitol and maltitol.

The concept forms the basis of the low-FODMAP diet, a structured dietary approach used to manage symptoms in irritable bowel syndrome and some functional gut disorders. The diet typically proceeds in three phases: an initial restrictive elimination phase, a staged reintroduction phase to test tolerance to individual FODMAP groups, and a personalization phase to maintain symptom control while expanding the diet as tolerated.

Evidence from randomized trials suggests that low-FODMAP eating can reduce abdominal pain, bloating and bowel irregularities in many IBS patients, though not all respond and effects may vary. Potential drawbacks include risk of insufficient fiber or nutrient intake if followed long term, alterations to the gut microbiota, and the need for professional guidance to ensure nutritional adequacy and correct reintroduction.

FODMAPs are not allergens; they are dietary components with variable effects on symptoms. Clinicians often consider them within a broader dietary and medical evaluation.