Has anyone switched from isomil to similac advanced?

I know I seem to ask a lot but I just want what is best for my sweetie. We came home from the hospital on similac advance and my daughter was so happy and content. Then about 1 1/2 weeks later she got a little constipated and the doctor switched her to isomil. She would also projectile vomit only once a day on the advanced. Well since switching to the isomil she cries constantly with hwe stomach and is so gy and reflux. I am thinking of trying to go bacj to the advanced but not sure. Has anyone else had this happen?