I dont have autism but I neither can eat gluten or dairy and when they gave me acid folic my belly got filled with gas and hurt like hell. I couldnt eat a thing until I stopped taking the supplements.

Have you tried stopping all processed food ? They put dextrose in most sauces/fries/sausages which is made of wheat. I heard about autistic people going back to normal once they stop all sources of wheat, corns and dairies.

Done a lot better since I evicted all dextrose, glucose syrup etc from my food. I also take chinese medecine drugs which helps a lot.