M.Q.
Hi ~ With him having an immature digestive system you really have to be careful w/the whey protein shake because whey protein is a derivative of dairy & therefore really hard on his little tummy. I would really suggest on cutting the dairy out of your system (usually takes about 2 wks before you will notice any change) while you are nursing. I had to w/both of mine & it really made a huge difference. HTH! Good luck!