Well, it was pretty much exactly what you would expect.
Spoilers, not that it really matters...
So this german doctor was supposed to be the best in his field, which is the separation of siamese twins. Now that he's retired he wants to continue his work, but now create. So he turns his 3 dogs into a centipede, ass to mouth style. (You only see a picture, the movie takes place after the dogs are already dead and buried.) Then he kidnaps 2 lost girls, and a japanese guy. He ties them up in hospital beds in his basement and shows them a little slide show of what he's gonna do. 2 people are to have all from teeth pulled (no biting, please), and lips removed, and 2 will have their assholes cut to match so they can be sewn together. Skin sections are pulled up from the ass cheeks and sewn onto the connecting face for a stringer connection. Surgery will be preformed on the knees to keep them from being able to extend them (and stand up).
One girl tries to escape, so he makes her the middle, which he says is harder on the knees. He lets them heal up, mostly on seditives, and then gets them to walk around and treats them like a pet. He feeds them in a dog bowl, and tries to teach them to fetch the paper. Japanese guy (the "head" of the centipede) shits in middle girl's mouth. Cops show up to investigate missing persons, doctor acts weird, them come back with a warrant. Cops kill doctor but he kills them, Japanese guy kills himself (cuts his throat with some broken glass), tail end chick dies from infection. The credits roll with the middle chick crying into the dead Japanese guy's asshole with her dead friend sewn to her own. I assume more cops will show up eventually and help her, since two cops just got a warrant to search the place and won't ever come back. But now she's lost her friend, is toothless, lipless, can't walk, and will never forget the time she spent a few weeks sewn to someone's asshole.
Highlights:
Paintings: The doctor has weird paintings/photographs of siamese twins all over his house, mostly babies and fetuses.
Ripping the IV out: You know how a medical IV is inserted in a direction toward your inner elbow? There's a shot where someone accidentally bends the line in that direction, ripping the vein out of the arm, up to the inner elbow. It's a quick shot, but that shit would still hurt.
Pulling the chick's teeth out.
Dude shitting in girl's mouth: I knew this was coming, but it was hilarious when it happened. The "head" guy is Japanese, so you get subtitles, "Shit! I've got to shit! ... I'm so sorry!" While she gags it down.
Ripping and bleeding while trying to escape: It's all just blood coming from under white bandages, but I was imagining stitches ripping open and exposing a bloody mouth with no lips/teeth.
Japanese dude cutting his own throat.
