I think I just hit my limit. I've always considered most horror films mainly as things where the most captivating aspect is to guess who dies next and with which traditional weapon. Even the best ones are 'best' because they have some good angle on the subject and genre, or because of some other celluloid perspective. But now.. never has the mere concept of the film been this disgusting to me and I've watched both 'Stoning of Soraya M.' (technically a drama but horror to me) and 'Das Experiment'. The cause: 'The Human Centipede'. If 'Scream' tests your limits, stay the fuck away from this one. I gagged at times and if I were any more inclined to react physically, I would have thrown up. 'Grotesque' has got nothing compared to the sick-and-twisted-o-metre of this one. Sick, sick, sick.
Watching the Saw franchise has made me think often as to what the hell is going on in these people's minds but this I don't really even want to know. Or Takashi Miike, for that matter. And this has two sequels. Not gonna watch those. I will read their synopses on Wikipedia to know how they've gone from here but not going to watch them any time soon.
Even on the risk of sounding like an American teen girl: gross!