Melody- just checking- the eliminations are temporary, in order to diagnose a potential allergy, right? You don't know that he is allergic to all 3?
If you ask your grocery store for "celiac" products, those won't contain wheat. This also means that fritos and cheetos are fair game... }( from
www.celiac.com:
Aside from corn and rice, there is a wide variety of other grains that are used in gluten-free cooking. We even use beans and peas (legumes, pulses).
The following can be milled into flour: amaranth*, buckwheat* (or kasha), chickpeas (garbanzos), Job's tears (Hato Mugi, Juno's Tears, River Grain), lentils, millet*, peas, quinoa*, ragi, sorghum, soy, tapioca, teff*, and wild rice. Many of these flours are available in health food stores. Some (like rice flour) may be available in grocery stores. (The products marked with an "*" are listed as grains to avoid by some physicians and celiac societies. See the discussion below about anectodal evidence and possible contamination of flours for more information.)
To improve the texture of gluten-free baked goods, most cooks use one or more of the following: xanthan gum, guar gum (though this sometimes has a laxative effect), methylcellulose, or a new product called Clear Gel. These can be obtained either through health food stores, specialty cook's stores, or some of the mail order sources listed below.
Oils popular in cooking include: corn, peanut, olive, rapeseed (canola), safflower, soy, and sunflower.
ETA: Melody, you say he is "sensitive" to smells and textures... can you give examples of what bothers him?