Former UFC heavyweight champion Brock Lesnar, who was recently stricken with a second bout of diverticulitis, had surgery on Friday, UFC president Dana White said.
"Brock Lesnar had surgery yesterday. They removed about 12 inches of his colon, and they repaired it," White said Saturday during a UFC 130 pre-fight television special. "He says he feels great. He's a little sore, but the operation was a huge success.
"We're hoping that he can be back by the first of the year. He's excited to recover and get back in the UFC."
Lesnar (5-2-0) was scheduled to face Junior dos Santos in a heavyweight title eliminator on June 11 at UFC 131 in Vancouver, British Columbia. But he pulled out of the bout on May 14 because of diverticulitis.
When he pulled out of that fight, Lesnar told ESPN.com: "I'll tell you one thing, I'm not retiring. This isn't the end of my fight career.
"I have a strong faith that there is a solution to every problem. We just have to find the right solution to fix this problem."
It was the second time Lesnar was forced to withdraw from a bout because of the illness. Lesnar pulled out of a title fight with Shane Carwin in October 2009 after discovering he had both mononucleosis and diverticulitis.
After surgery, Lesnar faced Carwin at UFC 116 in July 2010 and successfully defended his title with a second-round submission.
Lesnar, who is ranked No. 3 by ESPN.com among MMA heavyweights, lost the belt in his next fight -- on Oct. 3, 2010 at UFC 121 -- to Cain Velasquez by first-round TKO.
He was hoping to earn a rematch with Velasquez with a victory over dos Santos. The two were opposing coaches on "The Ultimate Fighter Season 13."
With Lesnar unable to compete, Carwin will now meet dos Santos at UFC 131, with the winner to take on Velasquez.
Franklin McNeil covers mixed martial arts and boxing for ESPN.com. Follow him on Twitter at www.twitter.com/Franklin_McNeil.