REALITY: While some elements were changed or left out in the transition from book to film, I think more changes were necessary to make this work better as a film.
Choke is the story of Victor, a guy who works at a colonial theme park. He also chokes on food in restaurants in order to be saved by wealthy people and sponge money off them in order to pay for the expensive hospital his mother is in. Victor is also a sex addict who attends sex addict anonymous meetings. His best friend is a chronic masterbater.
The storyline is typical Palahniuk stuff; a bunch of sordid, random ideas based on real life scenarios and myths all bungled together into a common theme. This makes for enjoyable reading, but Choke is kind of a messy film. There is a lot of flashbacks used, which in a novel makes perfect sense, but the big conclusion of the film, the pivotal moment, is a memory, something told in flashback. Perhaps this could have worked, but to me I felt like I was watching a novel on screen rather than a movie, if that makes sense. It's still pretty great, the performances are all strong and the cinematography and everything looks good, but there are some plot lines about placing rocks on an empty block, Victor being followed like he is the re-incarnation of Jesus, etc, that, while interesting, muddy up the film.
On a side note, Choke was adapted and directed by Clark Gregg, the S.H.I.E.L.D. guy from the Iron Man movies. Yeah! Iron Man!