Thank you for your query on Healthcare Magic.
Your grandson seems to have gastritis
mostly of a viral reason.
You can give an antiemetic like ondansetron
in prescribed dosage every 8th hourly to control the vomitings and nausea.
For gastritis you can continue antacids like lansoprazole
And the mainstay of treatment is to maintain hydration of the child with giving sips of oral rehydration fluids like Pedialyte
, coconut water, and lemon water.
Monitor his hydration status by activity, urine output, and skin turgor.
For fever give Tylenol as advised.
If the problem persist consult Pediatrician
for re evaluation and for treatment.
Hope I have answered your query.