Hi, My Baby Is 3.5 Months Old And He Is

Hi,

My baby is 3.5 months old and he is not drinking milk for the last 4 days. In the whole day he is drinking milk only 3 times in which the quantity of the milk is only 50- 60 ml . I have consult with my baby pediatricians .He said there is no fever or anything serious and gives only one medicine named as nutrolin "b" . Can you please help me on that. what is the issue and why my baby is not drinking milk..

Thanks in advance ...