Director Christopher Nolan updated Bane for the big screen but cut a sequence explaining his back story according to a story in Vulture. The Dark Knight Rises offers glimpses of why the villain dresses and acts the way he does but there’s no explicit origin sequence.
Costume designer Lindy Hemming was discussing other costumes for the final Batman film when she started revealing the flashback sequence to GQ.
“The thing that you should have seen during that sequence is [Bane] being injured in his youth. So one of the fundamental things about his costume is that he has this scar from the back injury. Even if he hasn’t got the bulletproof vest on, he still has to wear the waist belt and the braces. In that scene in the prison, where he’s learning to fight the same way Batman learned to fight, he’s wearing an early version of his waist belt. It’s showing support, but it’s not the finished one he eventually wears. He’s also wearing an early version of his gas mask, all glued together … If you look at the film, unless they’ve cut it—and I’m sure they haven’t—there’s a whole early section for Tom Hardy where he’s fighting and being taunted by people. He’s got chains on him, and he’s standing on a wooden thing while people are attacking him. And in that scene, he’s wearing a much more ragged, primitive version of the mask.”
When the interviewer told her that sequence is not in the final film she reportedly responded, “Well that’s an awful shame, but I suppose you have to cut things. I won’t elaborate on it too much, because it isn’t in the film, but there was another section that showed you why he had the mask and where it came from.”