With regard to the strange things found up men's backsides, the 2003 IgNobel prize for medicine went to the authors of a paper listing the various things found up there in A&E examinations. An amazingly diverse list! And, apparently every person who comes in with a dildo, beer can, toothbrush, or whatever up there, says they fell onto it while doing some unrelated activity (like hanging wallpaper) in the nude.