http://groups.google.com/group/alt.sex.enemas/browse_thread/thread/a930ff0e130485a8/b3d51068784b8aee?lnk=st&q=air+enema+floatation&rnum=1&hl=en#b3d51068784b8aee
http://groups.google.com/group/alt.sex.enemas/browse_thread/thread/a930ff0e130485a8/b3d51068784b8aee?lnk=st&q=air+enema+floatation&rnum=1&hl=en#b3d51068784b8aee
I recall one, but I have no clue where to find it online anymore.
It was about a spy who stole an experimental floatation device, and his plane went down so he had to use it. It proved to involve blowing him up like a balloon through the rear orifice.