Suggest Treatment For Reduced Appetite And Vomiting In Infant

Hi, My daughter is 3 months old and weighs 6.2 kg. she is an active baby and according to my doctor has been gaining decent weight. However for last 1 month her milk intake has gone down. She now has about 600 to 700 ml in a day. Also she has been suffering from reflux problem due to which she used to vomit often part or full feeding and completely refused feeds , excessively cry and arches her back she would only take her feed while she is asleep . She was hence prescribed on Rantac .5 ml twice a day for a month. And domstal .2 ml twice a day for a week. Subsequently she seemed fine however over the last one week again all simp toms have come back. This time I again gave her domstal but there has been no respite. She seemed uncomfortable and nauseatic all day and vomited at least 2-3 times a day part or full feeds. Sometimes even after 2 hours of having the feed. She also passes green coloured stools 2-4 times. Mostly watery without much matter. So the doc this time prescribed perinorm 1 ml thrice a day and lanzol junior half tablet once day. Is it ok to give perinorm for infants? Kindly suggest and let me have your views on the symptoms. Is the diagnosis ok pls?