Pneumonia and loose motions of baby.

My son who is 5month old.was diagnose for pneumonia.admitted in hospital for 6days .now at home.initially doctor gave antibiotic by iv.after 4days they stopped iv and started oral antibiotic cefixime.he is now suffering from loose watery stool after starting of iv.still now.today is day 4of oral antibiotic.he is having watery stool 8-10times in 24hours.after every feed,or during feed.after sharing this doctor started zinc gluconate.but there is no less.generally he passes stool after every 2_3days.his weight has been decrease.pee count is normal. My question is _is it ok that he is passing watery stool? 2_when the stool will be normal? Now how to take care of my baby?that pneumonia don't came back