The Human Centipede (2009)

The Human Centipede (2009), potentially one of the most disgusting horror films to ever be produced, hinges on the horrrible mind of a retired surgeon living in Germany. Two American women are on a road trip through Europe when their car breaks down in the woods. They find an isolated house and ask for help, only to wake up in a makeshift hospital basement with one other guy. The demented doctor (Dieter Laser) explains to them that he previously specialized in separating Siamese twins, but now wants to sew three unsuspecting people together in a line, connecting their gastric systems and creating a human centipede. The three all try to escape, but ulimately fail, and Dr. Heiter goes through with the surgery. Detectives come to the house to find the missing tourists, but they quickly become the doctor's next victims. 

The movie may be hard to stomach, but there's one redeeming shot of Laser's butt when he swims naked in a pool. It's relief you're going to need in this thriller!