Proponents of a low-FODMAP diet say it's less restrictive than going totally gluten-free, because people can re-introduce FODMAPs to find a threshold that keeps their symptoms in check.
Some researchers believe that many people feel better after eliminating wheat from their diet not because of an immune reaction to gluten or other wheat components but because they're reducing their FODMAPs.
FODMAPs are short chain carbohydrates (oligosaccharides), disaccharides, monosaccharides and related alcohols that are poorly absorbed in the small intestine. These include short chain (oligo-) saccharide polymers of fructose (fructans) and galactose (galactans), disaccharides (lactose), monosaccharides (fructose), and sugar alcohols (polyols) such as sorbitol, mannitol, xylitol and maltitol.