Call the doc and inquire if a diet change would help. After being treated for H. pylori most docs recommend that patients start acid suppression meds because H. pylori causes changes in the output of acid and their presence often results in gastritis.
If your son isn't seeing a pediatric GI person, you may also want to ask for a referral to one. And if testing hasn't been done - over and above finding out that the H. pylori was present - it may be time to have some done.
The medications he is on in Prevacid 15 mg 2xs daily and Ondnsetron 4 mg 3xs daily plus Maalox when needed.
No my sons pediatrician has not recommended any diet changes. In fact this has been going on for 2 years with no resolution. This all started with the H Pylori bacterial infection in his tummy.
If the meds you are on are proton pump inhibitors it could take about 7-14 days. It takes that long for the 'build-up' effect to take place. I hope your doc has also recommended a GERD diet as that may also help.