TweetUFC president Dana White announced today that former heavyweight champion Brock Lesnar has been forced to withdraw from UFC 131's main event due to a second case of diverticulitis.

Shane Carwin has been tapped as Lesnar's replacement and will meet Junior Dos Santos.

Lesnar was due to fight Dos Santos at the pay-per-view event, which takes place June 11 at Rogers Arena in Vancouver, British Columbia, Canada. The two serve as opposing coaches on "The Ultimate Fighter 13," which completed filming this past February and is currently airing.

It's the second time diverticulitis has derailed Lesnar's career, though Lesnar said it's not nearly as serious as his first. In late 2009, he was forced to withdraw from UFC 106 due to an unknown malady that turned out to be a life-threatening case of diverticulitis, a digestive disease of the intestines.

Lesnar was hospitalized for 11 days and lost 40 pounds in his first bout with the disease.

White said Lesnar's second bout was diagnosed recently at the Mayo Clinic.

"He's got some serious choices to make in the next couple of weeks whether to fight this thing or to take surgery," he said.

Lesnar said his second bout with the illness hasn't been as serious as his first. Surgery could potentially jeopardize his future in the sport.

Lesnar, however, said he's not retiring from the sport.

"I've just got to find the right solution to fix this problem," he said.

For more on UFC 131, stay tuned to the UFC Rumors section of the site.

TweetWell I saw him with his shirt off on the show and he looked great