Formula Change

Those who had to make the change in formula, how did you figure out your LO needed the change? What symptoms were presented? Did your pediatrician have certain indicators to know what type of formula your LO needed? We’re on day 3 of my LO crying nonstop & being inconsolable during the day unless she’s being fed, then right after she’s squirming, kicking, arching her back, red faced, & just miserable it seems. I’ve been using gas drops as recommended by the pediatrician, but nothing seems to help. She seems to only feel better at night, after a bowel movement (which is usually at night), or if she spits up. I’ve probably cried as much as she has the past couple of days it’s been so bad.