I won't try and describe it because it's impossible. Just go see it. It's not just simply disturbing, it actually conveys more of an "uncomfortable" feeling, since a lot of it can hit close to home. A lot of the characters are creepy, but realistic enough to make it even scarier. The soundtrack even has some black metal, so I recommend checking it out.
Basically, it's about some inbred, screwed up kids who live in a tornado-wrecked town with nothing to do but kill cats for money and sniff glue. There are girls who do weird stuff like putting tape on their nipples and pulling it off to make them bigger, and a guy with bunny ears who obviously symbolizes something, but I can't figure out what. The whole atmosphere of the film is nihilistic and dark, yet real. It's not an entertaining movie, but it will make you think. Like a psycoactive drug, it affects everyone differently, but is always enlightening. It's worth watching.
And the bathroom scene... MOST. DISTURBING. SCENE. EVER.
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