The anal canal is a very sensitive area, especially the deeper you go. Sharp objects, friction and certain materials may cause cuts, pain and or allergic reaction to the entire region. Believe us when we tell you that this is not pleasant. Be very careful about staying within your limits.

If you're into fisting as part of a little sado-masochistic action, make sure not to inflict actual pain in this area. There's nothing wrong with having a fist up there, but you need to be careful.