UFC's Michelle Waterson Has Made Fighters Crap Themselves, 'It Happens'

UFC badass Michelle Waterson says she's beaten up opponents so badly, they've actually defecated themselves DURING THE FIGHT ... telling TMZ Sports, "It happens."

The Karate Hottie is fighting this weekend at UFC 229 against Felice Herrig -- who famously made Justine Kish soil the Octagon during a UFC fight in 2017.

So, when Waterson stopped by the TMZ office ... we had to ask if she was afraid of Herrig pulling the same move when they square off on Oct. 6.

"I ain't worried," Michelle said ... "She ain't even gonna get there."

"Plus, I've made people do that stuff too!"

Talk about beating the crap out of someone!!!!!

Waterson doesn't name names -- but explains why the in-ring brown-down isn't as uncommon as one would think.