It's helpful if you empty your bowels before your squat session.
QFT. I forgot to do this before I lifted on Tuesday and had to concentrate on what muscles where pushin' when I was comin' out of the hole on squats... Wasn't bad on bench and rows, but squats when ya gotta crap suck.
I was working my way up to a new front squat PR when I suddenly had to poop. I dropped the bar and ran to the bathroom to have explosive diarrhea. I then came back and my current PR.