Dr has advised me to start giving Nan Pro to my 16 month old for a month due to some possible milk allergy. Now my boy has been drinking normal cow's milk since last 4 months. But today there was slight blood in his stool , possibly because he has been passing lil hard stool.

My ques- Is it advisable to give him formula milk? He might not accept the taste. In case he does, what if he doesn't switch back to cow's milk,?