After losing a bet with a fellow actor Rob McElhenney, Ryan Reynolds filmed his first colonoscopy and doctors made what they called a potentially life-saving discovery during the procedure.

The “Deadpool” actor, 45, and his Wrexham soccer club co-chairman, McElhenney, talked about what it would mean for the one who lost, about the bet the two made last year in a video posted Tuesday.

“At the heart of all sports is competition,” Reynolds says at the beginning of the video. Rob and I think we’re pretty competitive guys.” In the video, the two actors explain that they made a bet that if McElhenney learned to speak Welsh, Reynolds would allow the cameras to trail him for the procedure. However, McElhenney does so speaking in Welsh.

The two then made the decision to collaborate with the colon cancer awareness group Lead From Behind in an effort to persuade people, particularly men, to get the operation when the time comes.

The two explained they intended to demonstrate how the “simple procedure” can “save lives” in a YouTube video that was posted to Reynolds’ page.

“I would never normally have any medical procedure put on camera and then shared,” Reynolds said.

“But it’s not every day that you can raise awareness about something that will most definitely save lives. That’s enough motivation for me to let you in on a camera being shoved up my ass.”

Reynolds enters a hospital in New York and meets with a doctor, who describes the surgery as “stunningly effective” and taking about 30 minutes.

And in Reynolds’ case, it appears that this was unquestionably the situation. While still in recovery, appearing faint and making a joke about his IV being loaded with Aviation gin, the doctor presents the findings, he tells Reynolds that the scan found an “extremely subtle polyp” that he was able to remove.

“This was potentially life-saving for you, I’m not kidding. I’m not being overly dramatic,” he tells Reynolds. “This is exactly why you do this.”

McElhenney’s doctor stated they discovered three polyps, saying that they “were not a big deal, but certainly a good thing that we found them early and removed them.”

The 45-year-old star of “Always Sunny in Philadelphia,” who was overjoyed, jokingly claimed that he “won” the competition because he had two more polyps than Reynolds.

“I made a bet. I lost,” Reynolds shared in a message on the streaming site. “But it still paid off.”

“Colon cancer is preventable,” a message read across a black screen at the end of the video. “If you’re 45 years or older, ask your doctor about getting a colonoscopy. And help Rob and Ryan kick cancer’s a—.”