Brief Answer:
You may observe him and wait for antibiotic

Detailed Answer:
Hello

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Most common cause of diarrhea in this age is some viral infection (particularly if stool is not mixed with blood or mucus).
The main aim of management here is giving plenty of fluids to avoid dehydration.
I won't get worried if child is active,accepting orally well,passing urine, there is no vomiting and if stool is not mixed with blood or mucus.
Loose stool may persist for longer duration (may be 7-10 days).
I would like to know if you are giving zinc and probiotics as these helps in early recovery.
Here I would suggest you to wait and observe for next two to three days. You may get a stool test done to see if it is suggestive of infection which may need antibiotic.
Continue giving plenty of fluids and meanwhile if you notice any other significant abnormality consult your pediatrician.

I hope this helps.
Please let me know if you have any questions.
Wishing for your child's good health.
Regards

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