Changing formula again...?

My daughter is 2 months old and recently had to take her to the doctor because she has alot of colic. So the doctor suggested we change her to nutramigen lipil but because it is so expensive i asked if i could put her on enfamil gentlease and he said yes. So thats not working out so great so Im wanting to change her to nutramigen lipil now. When she was born she started on emfamil premium and the change of formula just started a week ago. And now I want to change her again. My question is, is it bad for the baby to keep changing her formula or to change it this soon?