Here's why a choke hold made this UFC fighter poop in the ring

When the match was done, it looked like the octagon was smeared with her feces.

Brilliant-but-messy strategy move? An unfortunately timed bout of traveler’s diarrhea? Actually, it was more likely the result of several factors blending together, says Rudy Bedford, M.D., a gastroenterologist at Providence Saint John’s Health Center in Santa Monica.

Most prominent was the fact that Kish’s opponent, Felice Herrig, put her into a rear naked choke hold in the match. When an action like that occurs, it can cause a Valsalva maneuver—a tactic performed by trying to exhale while keeping air from escaping from your mouth and nose. The maneuver is often used as a diagnostic tool to evaluate heart conditions, but most people are familiar with the trick as a way to clear stuffed-up ears while you’re traveling by air.

It also plays a part when you’re pooping, too. When you bear down to poop, you tend to instinctively employ the Valsalva maneuver. The breathing technique expands your lungs, pushes on your diaphragm, and puts pressure on your lower abdomen and pelvis areas, Dr. Bedford says. As a result, the muscles holding your stool in relax, allowing the poop to ease out.

So if the hold during the match triggered the Valsalva maneuver, it’s possible Kish’s body reacted the way it’s used to—by pooping. And that could have been compounded by the fact that she may have been holding her breath during the hold, too, which could intensify the effect.

But that’s not the only possible factor in play: The UFC fight environment itself may have been part of the mix, Dr. Bedford adds. In stressful situations like that, your fight-or-flight response kicks in, sending cortisol levels zooming upward. When that hormone surges, it can cause the abdominal muscles to tense even more.

And that can trigger something called peristalsis, or the involuntary contractions in your gut that move stool throughout your digestive tract.

“When the abs are under that much pressure, it can cause peristaltic waves, and that will result in bowel release,” says Dr. Bedford. “This isn’t the first time a fighter has had to deal with that issue.”

That outcome is rare, he adds, but just the chance is enough to cause many athletes to tweak their pre-fight strategies to reduce the risk. For instance, Dr. Bedford says many MMA fighters will eat only up until a certain time before training or a match. Also, it’s fairly common to have a bathroom poop stop before the mat. Habits like these can be helpful for non-athletes as well, especially those prone to nervous poop moments at the gym.

At least Kish showed humor about the incident. Tweeting after the match, she noted that she’s a warrior, she’ll never quit, and #Sh*tHappens.