Frank Mir: Brock Lesnar's MMA career 'would have been different' without diverticulitis - MMAmania.com
And according to his bitter rival, Mir, had Lesnar never gotten the life-threatening stomach disease, Lesnar's MMA career would have been drastically different.
His words (via New York Post):
"Honestly, I think the guy got so ill, he just couldn't do it anymore. He had to leave or his quality of life wouldn't have been normal. We didn't get to see the Brock I fought. Had he not been ill, things would have been different."