DH has celiac disease, and we eat at Disney all the time. Most larger CS locations have an allergy menu that lists several choices which are suitable for various allergies (for example, they may say a selection is suitable for wheat, soy, and dairy allergies), and you can choose one of those "off the rack". Just ask a cast member before you get in line and they'll give you a card with the allergy menu. Alternatively, you can ask for a manager and they will speak with you about specific concerns and may be able to alter another menu item (by leaving off a sauce, for example) to suit your needs. Most places have gluten-free bread or rolls and can adapt many of their sandwich selections using them. Sunshine Seasons at The Land in EPCOT has a whole counter that's allergy friendly; I think everything there is actually gluten-free. At smaller locations (carts, walk-up windows), you can ask for their "ingredient book" to see what's in a particular item. Desserts are limited, but many places have pre-packaged gluten-free cookies or brownies. DH likes Mickey bars, popcorn, creme brulee, slushies, and soft-serve strawberry sundaes, but before eating any of them I'd double-check the ingredient book in case they've recently changed suppliers or formulations.