How long do you try a formula before you decide its not the one? I originally planned to EBF. We had to start supplementing with enfamil newborn when we were in the hospital because of my low supply. We had her on it for 5 weeks but she was so gassy and fussy. Her doctor suggested switching her formula so we did enfamil gentlease for 9 days but it was making her stools hard and she would scream when trying to go, so I slowly transitioned her to similac sensitive. Today was the first day she had full similac bottles. Every time she ate today, she screamed for what felt like forever afterwards. She drank it fine though, so I know its not because of the difference in taste. I don't know if its her just getting used to it or if we should try something else? I started the transition Wednesday so it's only been two days. Her stools are now more liquidy and she doesn't seem to be in pain when passing them.