Question about 4.5 month olds poop.?

My baby's poop has always been watery. Well I changed her formula to a diff brand she was on similac sensitive and I tried changing to parents choice sensitive. The ingredient is the exact same except the parents choice has 2.5 less charbohydrates. So figured might as well try saving an extra 10 dollars if its the exact same stuff. Well she's pooped twice while on it and her poop changed to more of a creamy not so runny poop. Is it the formula or is it suppose to be more creamy like that? Best I can describe it is like mash potatoe texture. So kinda creamy and thick. She had no problem doing it but I noticed it changed. Should I go back to similac or is her poo normal suppose to be creamy not watery?