But Boyle scoffs at critics who say Trainspotting encourages people to pay that extreme a little visit. Yes, he admits, the first third of the movie is a drug-frenzied rush, but the last hour is a plunge into heroin's physical and emotional wreckage. ''The heads of British industry are saying to you, 'This is not the right kind of film to make, because you might be encouraging people to try it,''' Boyle says. ''That's just silly.''
''People criticize it because it dares to show the truth: that people take drugs because they are pleasurable,'' adds Macdonald. ''But we also show that if you take too much of them, there's a serious chance that they'll f--- you up.''
But forget heroin. Right now, Ewan McGregor is mainlining cholesterol. Seated in a New York trattoria just off Broadway, the homesick Scot announces his desire for ''comfort food,'' and satisfies it with a wheel of smoked salmon, a bowl of butter-soaked fried potatoes, and a small mountain of sauteed calfs' liver. ''Fookin' hallelujah!'' he proclaims as the waiter supplies the vein-clogging repast.
You don't meet many young stars who admit they have a lust for liver. Then again, you don't meet many young stars who crawl into stardom the way McGregor has. Would Tom Cruise tolerate a camera inches from his hindquarters, as McGregor did during Trainspotting's infamous toilet scene? ''The cameraman's underneath there, and my big hairy ass is in his face,'' McGregor recalls with a snort. Another time, an actress playing a nurse jammed a needle into the wrong place. ''She missed the vein,'' McGregor says. Blessedly, Robert Carlyle had better aim. At one point Carlyle, playing Trainspotting's trip-wired psychopath, Begbie, slammed a rusty pocket knife between McGregor's legs. ''We had to be very careful,'' says McGregor, 25. ''He said that as long as he kept his arm straight there was no danger of it going into my nuts.''
If Boyle wanted Trainspotting to take the audience to the extreme, he found the perfect ambassador in McGregor. A sweet-natured family man with a wife and baby back in London, McGregor adores Jimmy Stewart movies, waxes sentimental about his pastoral childhood in the country town of Crieff, and completely bypassed Britain's drug-fueled rave scene back in the '80s. ''I missed all that,'' he muses. ''I had no experience with drugs when I was growing up.'' Which made him just the guy to play Trainspotting's twinkle-eyed dope fiend once he'd shaved his head and lost 26 pounds, of course. ''We wanted somebody who had the quality Michael Caine's got in Alfie and Malcolm McDowell's got in A Clockwork Orange,'' Boyle explains. ''You have a character who is actually repulsive, and yet there's a charm there that makes you feel deeply ambiguous about what he's doing. You're drawn to him.''
Casting was just one way the team made Trainspotting more accessible. Boyle dubbed over a few minutes of dialogue to help American audiences slog through the thickets of Scottish brogue; he also trimmed two scenes a needle slipping into an arm, and a young girl straddling McGregor during an orgasm to make sure Trainspotting got an R rating. ''We got a message back from the censors that they thought the girl was enjoying herself too much,'' Boyle chuckles. ''So we cut it in half.'' But he's not complaining. ''You have to be realistic,'' he says. ''We want an R rating because we want the film to appeal to as many people as possible. It has to earn its place in the market and dust the pants off Twister and Mission: Impossible.''