Hi Doctor, My 3.2 Years Old Boy Having Loose Motion

Hi Doctor, My 3.2 years old boy having loose motion from last 4 days, frequency inst very high only 2 or 3 daily. Initially two days he vomit twice but it stop but unfortunately loose motions are still going on.
we are given him Kaptin and flagyl one tea sponge.

need you humble advise what we should do now, please help us