Hi there ~
I understand your concern. It seems to me like your son has a problem with eating known as binge eating disorder
(BED). I would bring this to the attention of a qualified psychiatrist
who can help with medications. I also feel like he is also having problems with gastritis
and needs the attention of a GI doctor as well. I would recommend that you first get an upper GI endoscopy
done for your son as well as H Pylori testing. It seems like this is a condition that can be easily dealt with when you see a psychiatrist.
Take care and have a lovely day!