Thank you for your query on Healthcare Magic.
I advise you to continue the medication as advised by your Pediatrician
Give sips of oral rehydration solutions to maintain hydration.
Appetite usually decreased in children with infections especially with gastrointestinal infections.
Nothing to worry, the appetite will improve as the infection subsides.
Monitor his hydration by his urine output, activity, skin turgor, and tongue moisture.
Hope I have answered your query.