Brief Answer:
He needs ORS as needed

Detailed Answer:
Hello and welcome to Ask A Doctor service.

I have reviewed your query and here is my advice.

The most common cause for loose motions in a baby is viral gastroenteritis due to Rotavirus, etc. They recover by themselves in few days. They need extra care during such illness.
Among medicines we donot recommend antibiotics in a baby. He should be given ORS or water after every motion. If he develops vomiting then he can be given medicine for vomiting like ondensetron syrup. If he has fever more than 102f then he can be given paracetamol syrup 3-4 times a day.
Milk may be given after giving some solid food like cerelac. Juices must be avoided during diarhea.

Hope this helps. Let me know if I an assist you further.
Dr Vaishalee

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