Hilarious in Hindsight: In the book, 1907 Battle Creek is reminiscent of 1999 Silicon Valley, with cereal manufacturing companies instead of dot-coms.
Squick: The novel's depiction of Homer Praetz getting electrocuted in the 'sinusoidal bath'. His eyes explode and he bites off his tongue.
The film:
Nausea Fuel: The movie jumps from a shot of Will Lightbody receiving an enema to a shot of dark beer being poured into a glass. Also note that Kellogg grabs Will's tongue with the same gloves he wore while handling a stool sample earlier.
