Thanks for your query.
Your child is having gastroenteritis
which is mostly viral in nature and takes few days to subside.
Most important is to maintain hydration.
Give oral rehydration solution sip by sip after each loose stool
Give coconut water,lemonade,curd,rice porridge.
Give lactobaccilus for 2 to 3 days
For vomiting give domperidone
as per dose.
In case symptoms persist get him evaluated by pediatrician
for proper management.
Wishing your child good health.