The insomnia after eating sounds a bit like me. Food intolerance gave me terrible insomnia. I have mast cell and autoimmune problems, candida, and gut health problems, pyroluria, and a slew of other things as well.
I recently tried Parasym Plus and it was wonderful for my pain, but I couldn’t sleep on it. If that happens to your son, or either way, you may want to consider magnesium. Not just any magnesium. Try a few kinds. Specifically magnesium oil on the feet at night, Magnesium Threonate (knocks me out for a few hours), magnesium malate is good for absorption, magnesium glucarate if there is a deficiency. Magnesium threonate is supposed to be good for building cognitive function.
Altering my diet pulled me out of depression, and it’s helped with autoimmunity, but I am still working on that.