Thanks for your query.
Your child is having diarrhea
which is mostly viral in nature and take few days to settle.
It is very good that he is active.
I suggest you to give him oral rehydration solution sip by sip after each loose stools.give coconut water,curd,banana,boiled potato.
for 2 to 3 days and observe any features of dehydration
,decrease urine output,increased thirst,sunken eyes and in case there ia any get pediatric consultation.
Wishing your baby good health.