Since your baby is suffering from Gastroenteritis
continue with the medications as prescribed by the docter.
See to it that he is kept well hydrated and passes adequate urine.Its good to know he has received the rotavirus vaccine
.However there are multiple bugs which can cause diarrhoea
and rotavirus will give protection against only serious rotaviral infection
.You mentioned he is eating well, has he been weaned?If you are giving him supplementary feeds then you could also give rice kanji,thin curds and restrict his milk intake.