My baby is 9 weeks old and she has been on similac lactose free milk but now all of sudden she's refusing to take it, we thought the problem might be the nipple flow was too slow for her and we changed that, nothing happened and she still rejecting the milk, so husband tried giving her enfalac(not lactose free) she drank 4oz straight. But right after she pooped and it was diarrhea. Should I change to enfalac lactose free? Would it taste the same with similac LF? Thank you ladies.