3 month old crying while pooping

Kelly

So since birth, my daughter has been crying every time she poops. Her face gets all red, she arches her back, and cries like she is in pain. The doctor said that it was normal, and she should grow out of it by 3 months. Well she is 3 months and no improvement. Maybe even a little worse. Also every single time her poops are huge, and are explosions out of the diaper all the way up her back. Yes, the diaper fits and we have tried several different brands. No diaper could hold the amount of poop she has. She poops once or twice a day. For the last month she has been doing half pumped milk, half formula. The past two weeks she’s been on formula only. No difference whether she drinks my milk or formula. I am going to call the doctor on Monday, but has this happened to anyone else’s baby? Normal or could she have an intolerance or allergy? I hate seeing her in pain.