I can totally understand why you are so angry and needing to vent, my ds was the same age as yours when he started having gastric problems, acid, vomiting back small amounts of meals, constant diarrhoea, sometimes with blood present and at the same time his growth completely stalled. He was under a paediatrician anyway, as he has ASD and was going through the assessment process for that and the gastric issues were checked to try and ascertain if they were anxiety related or something physical.
With all this going on his teacher failed to inform us that he had brought back small amounts of his lunch on several occasions. At that time he wasn't capable of recounting his day (he has sequencing issues) so getting information from him about what happened during his school day wasn't easy at all.
The information eventually came out when the paediatrician and dietician agreed that we should eliminate gluten from his diet and we informed the school. The teacher had to ask me what he could have as an alternative when they were doing multi-cultural food tasting as a class activity and just dropped it into the conversation that he'd been vomiting small amounts at school for a while.
Obviously I was angry, but like you chose to vent elsewhere, as ranting a the teacher would be pointless and just cause even more problems.
Essentially my ds' gastric issues were sorted out in spite of the missing information from school. It might have speeded things up had we known he was vomiting more than we believed, but not by much.
It does sound like the military hospitals are only really geared up for treating adults. Is there any chance you could go off base to access more specific paediatric care, as they would be far more sensitive in their handling of him?