This silliness is called ZOMBIE ASS: TOILET OF THE DEAD and it is an actual movie that shockingly is not some type of scatological porno. Man, the Japanese are a wild culture.
Click ahead for the insane trailer.

Wracked with guilt over the suicide of her sister, who was
tormented by high school bullies, young karate student
Megumi accompanies a group of friends on a trip into the
woods. Attacked by a crowd of poop-covered undead who
emerge from an outhouse toilet, the group seeks refuge
in the home of the strange Dr. Tanaka, who conducts
experiments on the zombies … and who has another fate in
mind for the five strangers. Can Megumi s karate help them
escape, or will she have to rely on the liberating power of
f**ts to save the day?

http://www.youtube.com/watch?v=qdQts9i6wdI