My Baby Is 3.5 Months Old He Having Green Poo

My baby is 3.5 months old he having green poo from last 6 days. Doctor had given zerolac n Lbz powder but my baby not taking zerolac he don't like taste of it, suddenly he got cough n little running nose with green watery poo. Is Nutrolin b is good medicine for him. He don't have fever. We are worried as last so many days he was on medicine for cold n cough n gases. We are giving him Ambrodil syrup for cough, colicaid, lanzol tablet, LBZ sachet n now nutrolin b for poo. Please suggest why he having green poo he is on mother milk only, no formula we have given. Without doctor recommendation we have given nutrolin b just now as he having watery green poo. 2.5 ml