Welcome to NeuroTalk. I am sorry to hear of your son's injury.
Can you give us a better explanation of his injury. Did he fall and hit his head and continue falling and hit his head again? Or was this a coup-contra-coup injury?
Neck injuries that can happen during the head injury can cause gastric problems. A likely injury would be at C-6 to T-3, between the shoulder blades. I suffered an injury at T-3 decades ago and lost 20 pounds in 2 weeks. A Stanford GI doctor could not find the problem. A chiropractor finally found that I had dislocated a rib that was inflaming the nerves that lead to my stomach and esophagus. All I was doing when I injured myself was splitting firewood with a splitting maul. I swung hard and popped a rib out of place.
Hope this helps you get him the help he needs.
My best to you both.
Mark in Idaho
59 years old, retired due to disability, married 33 years, father of three, grandfather of four, Suffered a serious concussion at 10 years old (1965) stopped most driving after last concussion at 46 years old (2001), Post Concussion Syndrome/Multiple Concussion/Impact Syndrome with PTSD, immediate and short term visual and auditory memory problems, slowed processing speed, visual and auditory processing difficulties, insomnia, absence seizures, OCD, 14 concussions since first concussion at 8 years old, Taking paroxetine for 14 years and gabapentin for 12 years. Added L-Tryptophan and successfully stopped all paroxetine after 3 months of tapering down. I currently take 500 mgs of L-Tryptophan when I wake up, 500 mgs after breakfast with my vitamin regimen and 500 mgs late in the evening.
As of Nov 15th, Due to high stress issues resulting in PTSD, my docs put me on three meds. Clonazepam (Klonopin, a dreaded benzo but only for 30 days ) .125 mgs twice daily (Doc prescribed .25 mgs twice daily but half a tablet is doing good) , citalopram (Celexa), an SSRI , and olanzapine (Zyprexa), an atypical anti-psychotic before bed. I have lost over 30 pounds since mid July. The olanzapine is supposed to help me gain some of it back but it has just stopped the weight loss. They took me off the gabapentin. I am feeling better than I have in years.
I am also taking L-Theanine to help with GABA regulation
"Be Still and Know That I am God" Psalm 46:10