Ailing cage fighter Brock Lesnar has developed a serious intestinal disorder that requires surgery, Ultimate Fighting Championship boss Dana White told TMZ.com Monday.

Lesnar, a 265 lb. former wrestler and football player, collapsed and was reportedly hospitalized last week during a vacation in Canada. On Saturday, White told various sources that Lesnar was in dire condition.

"He's not well. He's not going to be getting well anytime soon," White told reporters after a UFC event in England. "He doesn't have cancer or AIDS or anything like this, (but) he's got some problems."

On Monday, White clarified his diagnosis somewhat. He also said that Lesnar is back in the U.S. and that he might be admitted to the Mayo Clinic for surgery. According to White, Lesnar, 32, might never fight again

Lesnar himself has not been heard from since cancelling a scheduled bout three weeks ago. Shortly thereafter, UFC announced that Lesnar had contracted mononucleosis. Rumours swirled that he had swine flu. Things appear to be going from bad to worse for the superstar mixed-martial artist.

In college, Lesnar was a dominating wrestler. After school, he used his impressive bulk and outsized personality to switch over to the theatrics of professional wrestling. He was a huge draw for World Wrestling Entertainment.

In 2004, he decided on a mid-career switch to professional football. Despite no high-level experience in the game, he was given a shot by the NFL's Minnesota Vikings. He only played pre-season before being cut.

At age 30, he decided to switch professions again. He soon signed on to fight for UFC. In July, he won a championship belt.

UFC has had no trouble drawing huge crowds and lots of pay-per-view customers. Credibility, though, continues to be harder to come by. News of Lesnar's mystery illness has been greeted by skepticism by some blogs outside the mixed-martial arts universe.