Please accept my apology for not replying sooner but I have been having PC problems after starting constructing a reply which I never got finished on my other PC. Something has damaged a PCI express connector on the motherboard and no card works correctly in the slot. My PC crashed and after restarting the card would not work and no card now works in the slot. I now have two broken motherboards but at least this one is working to some degree but not 100% as the SATA connectors are not functioning correctly and I have been having problems with the display going into standby and not resuming no matter what I have tried. The reply I was constructing was on the other PC and ATM that is very unstable.
I do remember that I suspect that your son has a problem with his pituitary which might explain some of his problems with regard to his development. How old is he?
One herb which can improve the pituitary function is Tu Si Zi (Dodder Seed) which is frequently taken with Gou Qi Zi (Goji berry/wolfberry). In animal tests Tu Si Zi increases the weight of the pituitary gland and hence improves it's function. Together they can tone the kidney energy as well as improve the pituitary function and Tu Si Zi is meant to help with elevated liver enzymes which are common when Increased Intestinal Permeability Syndrome aka Leaky Gut is a problem which I think your son must be experiencing.
Dosage is up to 15 grams /day and two cups a day is usual. I boil a large pan which lasts me about 3.5 days. I would not be without it and I have been taking it for many years. It helps to lower cortisol which is often elevated and has many negative effects in such conditions. Cortisol increases saliva production which needs to be kept to a minimum! I bet that your son gets increased saliva whenever he eats due to histamine production. The only real negative is that it can be a little constipating. Taking some lecithin should deal with that better than any of the things you have been using because it addresses the causes of the constipation. Taking too much can loosen the bowel too much. I use powdered sunflower lecithin but there is a shortage of it ATM and the prices have risen quite dramatically due to that. Even the American sites have no stock of it ATM and the place I was getting it from also has no stock so I have had to go to ebay but the price is far too high IMO.