In a 5 month old baby with apparent gastroenteritis
in my opinion starting netilmycin inj was unwarranted without doing any investigation. You can think of stopping netilmycin inj & get urine & stool examination done along with CBC & CRP as in this age urinary tract infection
can very well present as fever vomiting
& loose stools.
Lactic acid powder & Pyrigesic drops should continue but try to avoid motinorm drops as it can have significant side effects in young babies. Hope I have cleared some doubts.