Seconded. For our situation, it was fructans and polyols (to a lesser extent). Gluten seems to be a non-issue for us, except that wheat products also tend to be

Seconded. For our situation, it was fructans and polyols (to a lesser extent). Gluten seems to be a non-issue for us, except that wheat products also tend to be high in fructose and oligosaccharides. If you're reasonably diligent about keeping to the diet restriction and only reintroducing one food group at a time, it's possible to be quite precise about identifying what compounds might be a problem.