"bloaching" (noun) (etymology uncertain) is the act of having a friend insert a balloon into one's anus and then blow up said balloon until it is firm at which point it is either exploded or removed.
The word can be back formed to "bloach" (verb).
"I hear that Tom Cruise is into bloaching in a big way."
"Why is he looking so glum?"
"He tried autobloaching and one got stuck up there."