I have a Husband with Celiac and a son with Autism ( who has the DQ2 and DQ8 gene). It wasn't until I discovered that my then 15 month old son had Celiac ( he had diarrhea, reflux and pain from the day he was born) and put him on the GF diet did we know my Husband had it, had it for thirty some years.
The point I need to make is, does my son have autistic enterocolitis or Celiac? He has not had a biopsy, or endoscopy. The positive DQ testing and the Gluten intolerance was enough proof for me.
My son's Autism improved, his language and focus improved and his behavior changed after the diet change, and most importantly he gained weight and started on the road to healing. He had dark circles under his eyes, was always sick with everything from viruses to ear infections. It was truly amazing how he became a new child, he felt better but couldn't tell me