Thanks for your query.
is mostly viral in nature and takes few days to settle.
Most important is to maintain proper hydration.
There is no need to start antibiotic.
Give oral rehydration solution sip by sip after each loose stool
.give coconut water,mashed banana,boiled potato.curd,rice porridge.
Give lactobaccilus for 2 to 3 days and complete zinc for total of 14 days.
In case symptoms persist get him evaluated by pediatrician
Wishing your baby good health.