Thank you for your query,
Your child seems to have acute gastroenteritis
Maintain his hydration by giving sips of oral rehydration solutions.
Monitor his hydration by his activity, urine output, and skin turgor.
Stomach pain is due to gastritis. You can give one antacid like child lansoprazole
after your doctor prescription.
if loose motions persisting or any signs of dehydration
Hope I have answered your query.