Down But Not Out: Brock Lesnar Declairs Diverticulitis Won't Stop … Lesnar, who defied odds and bounced back after he was stricken with diverticulitis in 2009, hadn’t been feeling himself for the past couple of months, and he knew deep down that something wasn’t right… again. … iAmJoeyRocca says: RT @JRsBBQ : Brock Lesnar out of Dos Santos fight due to reocurring issues w/ diverticulitis . Shane Carwin will replace ailing Brock. Best 2 Brock.