Thanks for your query,
Give him lactobacillus
sachet for 3 to 4 days,
Give oral rehydration solution sip by sip.
Give coconut water,rice porridge curd.
Decrease amount of milk.
Keep bottom dry,apply mild steroid
cream 2 to 3 times,pat with wet cotton gently.
If symptoms persist get him evaluated by pediatrician
Wishing your baby good health.