Hello,
I have a strong feeling that your son's sub category of autism is the treatable kind....
The stomach symptoms are very indicative of that.You might need to find a DAN Dr to work you through on this,but I can tell you up front that there are a spectrum of tests out there to guide you....the leaky gut most likely might be restored with probiotics, or oral vancomycin...which would not subject your baby to a lot of side effects....it has a localized action in the gut to wipe out the overgreowth of the clostridium bacteria which is in excess in this WONDERFUL AND ADORABLE kids.
I wish you the best of luck