According to a surgeon who was a supervisor on the movie, it is medically accurate. Of course, I'd rather doubt that doctor will have much business going forward, but you never know.
"Throughout the production process Tom Six stated his intention to create a film that was "100% medically accurate", consulting a surgeon during the creation and filming process.] Six has claimed that whilst initially reluctant to take part in the film because of professional reputation, after reading the script the surgeon consulted took a very strong interest in the procedure, devising a method that he believed would work in real life. Six claims that by using an IV drip to supplement the diet of the middle and back parts, the centipede would be able to survive for "years".
People will pay to see this?
Here's the plot if anyone wants to highlight and read. Don't get mad at me if you do! :
Plot
The film begins with the antagonist, Dr Heiter (Dieter Laser), kidnapping a truck driver by the side of a road. Later, two American tourists, Lindsay (Ashley C. Williams) and Jenny (Ashlynn Yennie), arrive at Heiter's house as they search for help after puncturing their car tire. Heiter drugs the women and they awake along with the kidnapped trucker in a makeshift hospital ward in the cellar. Heiter informs the trucker that he is "not a match" and kills him. When the women next wake, they are joined by a new captive, Japanese tourist Katsuro (Akihiro Kitamura).
The doctor explains that he is a world renowned expert at separating conjoined twins, but dreams of creating new beings that share a single digestive system by joining separate individuals via their mouths and anuses. He explains that his previous experiment, a "3-dog", died. However, he explains how he will attach the three human subjects to each other to create a "human centipede". Once the operation is complete, the doctor begins training the three to perform tasks. Katsuro, as the front part of the centipede, refuses to do as he is told, and the doctor beats him. When Katsuro has to defecate, Lindsay is forced to swallow his excrement and the doctor watches with great delight. However, Heiter eventually becomes irritated after being kept awake by the constant screaming of his victims and realising that Jenny is dying from blood poisoning.
A man and two women lie on a sofa in a living room with soft lighting and an abstract painting of conjoined twins upon the wall. They lie in a line on their left side, facing the viewer, with the man at the front and the two women behind him. They wear only their underwear and have bloody bandages on their knees. The man's upper body is out of shot beyond the right edge of the image. The first woman behind the man has her face obscured behind the man's buttocks and her hands are on his legs. The second woman lies in an identical pose behind the first woman. Behind the sofa is a man in his sixties with short dark hair, wearing a dark suit and red tie. He leans over the three, looking at the first woman's head.
Dr. Heiter surveys his completed "human centipede"
Two police detectives, Kranz and Voller, visit Heiter to investigate the disappearance of tourists in the area. After the detectives leave, Heiter informs his surgically-attached captives that Jenny will soon be replaced by two new parts. Katsuro stabs him with a scalpel and the "centipede" attempts to escape as Heiter crawls after it. Katsuro faces the doctor with a piece of broken glass in his hand and tells the doctor he "deserved" to become an insect, due to prior ill treatment of his family, and then commits suicide with the glass. At this point, the police break into the house and Heiter crawls away to hide in his swimming pool room. Kranz is shocked as he discovers Heiter's victims, and soon finds Voller dead in the swimming pool near an armed Dr. Heiter. Heiter and Kranz shoot and kill each other. Jenny finally dies from her blood poisoning, leaving Lindsay alone in the house, trapped between her deceased fellow captives.
...and the masses continue onward in their search for entertainment.
I'm not sure if it's supposed to be a dark comedy, indie shocksploitation, or what, but it certainly will get people talking.
As to "medically accurate," find some quack somewhere looking to get his name out there, and you've got your backing from the medical field. Now, gather a large panel of the top surgeons in the world, and then we'll see if it's accurate.
ETA - I found it odd that this thread was right next to the "What's for dinner" thread.