So I look my daughter to her GI appointment yesterday and they tested her poop and it had blood in it so he said she had a milk allergy. He put her on Similac alimentum. She had already been on Similac advance, Similac sensitive, and Similac total comfort. The reason for her formula being changed is because she will scream bloody murder when she uses the bathroom and she's very constipated. So this makes the 4 formula. Once I left the office it was time for my daughter to feed so I started her on the new formula. Ever since she has been super fussy. It's been almost 24hr and she is refusing to take naps and just really fussy all together. Is this normal? How long does it normally take for a baby to adjust to a new formula?