It's not castration!
I've noticed how many people use the word "castration" in discussion of this film's ending. I don't know anything but the unrated version, so I can't vouch for possible editing and misleading, but there is 100% no doubt that Jordan's entire set of equipment gets lopped off by the hedge trimmers in the attack. What's left of it is fed to Red.
Castration would be livable (though I might not want to), but this was certain death. He bled to death, chance of 99%. He was just involved in sex with a lot of blood flowing there. The blood in the scene is the explanation of that. He would have bled to death right there. This makes sense, too, if you buy into the fall-from-innocence theory, and how innocence always dies. (And I'd say that if my stuff was chopped off, I would FIND a way to be dead...)
It's by far the only film that I've been genuinely disturbed by. It's just brutal, and scary... but it ain't simply castration, kids.