This is absolutely correct and was a horrifying discovery when I first started doing stretches and leg/ab stuff. I was in the gym for 10 minutes and immediately had the overwhelming urge to shit and within 2 minutes I was in the bathroom and I was *literally* 5 pounds lighter. Anything revolving around abdominal/pelvic muscles is absolutely the cheat code for shitting, it’s why so many people recommend stretching if you’re constipated