Bam Margera says he underwent a hernia operation shortly after taking a kayak over a 100-foot cliff in Oregon this week. "Just did a 100ft tandem kayak jump with pro kayaker Steve Fisher in Oregon!" Margera, 32, said via Twitter Thursday. E! said the "Jackass" troupe member tweeted one picture of himself jumping, and then another of him in a hospital bed after he underwent a hernia operation as a result of the drop.