He is healthy, playful, and naughty

Yesterday, Daniel vomited twice.
I don't know what happen to him.
He is not active like usual. He feels so weak...
Not like usual day, which he is so playful and naughty!
We went to c his doc, Dr Ho, but then the doc just gave him oral dehydration salt.
So, we don't actually figure it out what had happen to him.
Alhamdulillah, he is fine until now.
I gave him drink milk just now, and he drank.
Insya allah, he will be fine once he wakes up!