Basically chiming in with everyone else here. Handle it off-screen. You can imply a lot without actually forcing the reader to "watch" the act. Actually, I think implied violence can be just as disturbing if not more so than spelling things out move by move. Letting the reader imagine what might have happened allows them to scale it to their own comfort level. Also, I've heard this in regards to rape, but I think it's a similar situation here. Portraying the actual act gives power to the perpetrator, not the victim. And if your victim (or someone related to) is the protagonist, that's the person to focus on. Their feelings, how they deal with it, etc.
Personally, I used to be able to read this stuff. Now that I have a kid? I almost started crying last night when we watched an episode of Deep Space 9 where a mother is separated from her children. I'm amazed at how little I'm able to handle of kids getting hurt, now.