Hello
In my opinion your 11 years old son has some dietary imbalance so that he is feeling such type of symptoms as
nausea ,
vomiting , stomach pain , so please do as .
1 Try raising the head of your son bed about 4 inches with blocks.It also might help to avoid eating or drinking for 2 hours before your son lie down.
To help control stomach acid one should not eat chocolates or spicy or greasy foods or pizza, burger or drinks with caffeine in them.
When such patient visit in my clinic I advise them to take
antacid ,but few patient don't respond to antacid , the need drugs like
proton pump inhibitors like pentaloc-D one or twice in day.
2 The 2nd reason of such symptoms may be due to over eating , so please take care about that.
3 Tension or
anxiety is the another most common cause of such symptoms in teens , so also take care about that , if any.
Good luck.