My mind was blown when I first (not to long ago) heard that some people stand to wipe their ass. It just one those thing that you don’t realize someone could do differently.
I personally think it’s disgusting. When you stand and wipe you are bringing the pooh out the plane of toilet. The pooh (and butt) must remain in or less then 1 (one) inch above the bowl.
http://i38.photobucket.com/albums/e104/00xj54/pooh-1.jpg
Pooh should never, not by any means ever, be outside the pooh safety sanitation zone)