If my lover decides he is gonna make love to my asshole, he gently prepares me with a warm inert solution. This is just meant to clear the way to his anal probing of my tight ass.
If I am in trouble there are many enemas and at least one very hard to hold enema like M&M or a very soapy solution for an extended time. I also suffer the cane, razor strop, belt and a wicked wooden ruler..