Figure 2.

Ingested fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAPs) are poorly absorbed in the small intestine. Their small molecular size results in an osmotic effect, drawing water (H₂0) through to the large intestine. FODMAPs are then fermented by colonic microflora, producing hydrogen (H₂) and/or methane gas (CH₄). The increase in fluid and gas leads to diarrhea, bloating, flatulence, abdominal pain, and distension.

Reproduced from Barrett JS, Gearry RB, Muir JG, et al.¹⁰