Feces (symbol)
Feces is shown repeatedly in the film, and symbolizes the biological decay that heroin leads to. We first see it in “The Worst Toilet in Scotland,” as it encroaches on Renton’s personal space, while he tries to cleanse himself of it. Later the explosion of feces that Spud causes in Gail’s family home foreshadows his return to drugs, and the feces smeared on the walls of Tommy’s apartment indicates the way that heroin finally got a hold of Tommy, and began to make him waste away.
Youth/Pop Culture (motif)
Danny Boyle uses popular punk rock from the time period to bring energy to an otherwise-depressing subject. The soundtrack and pop images of the film also reflect the characters’ interests—the film opens with "Lust for Life" by Iggy Pop, and features several other tracks by him, while the characters repeatedly refer to him as one of their favorite artists. The soundtrack also features many more popular artists and bands, including Primal Scream and David Bowie. This use of ‘rock n roll’ in the film formed the basis for much of the criticism that it glamorized drug use. However, it really functions as an immersive experience in the world of our narrator, not a glamorization of addiction. The choice of songs is even quite tongue-in-cheek at times, pointing out how miserable some of the situations are; for example, as Renton overdoses, “Perfect Day” by Lou Reed plays. Additionally, Sick Boy is constantly making references to pop culture (mostly about Sean Connery), and at times conversations about pop culture seem to be the only thing that interests them, outside of heroin.
"Trainspotting" (allegory)
The film title itself is an allegory for the lives of the characters. In literal terms, trainspotting is a hobby in which a person stands at a vantage point near train tracks and documents the train numbers as they go past. Though the scene in which they actually address the activity of “trainspotting” was cut from the film (it does happen in the book), the title still stands to point out the depressing reality of Renton’s life. It represents a useless activity, in which the actor accomplishes nothing and watches the world pass him by. Renton’s lifestyle, and his heroin use, is just such a futile activity, and the allegory of the title highlights the way in which Renton’s life is stagnant because of his addiction.
Futility and pointlessness (motif)
Trainspotting depicts characters engaged in an almost endless cycle of futile and pointless actions, and the question that looms at the end of the film is whether Renton’s final escape and promise to start over will turn out to be futile as well. Though we may hope, and find some evidence, that this final change is not futile, it certainly would not be out of character for Renton to give up and return to drugs. He opens the film by commenting on the pointlessness of life when he says “who needs reasons when you've got heroin?” and he goes on to break every promise to himself throughout the film, making nearly all of his decisions come to nothing. Other characters demonstrate this motif as well: Begbie is pointlessly violent and Tommy’s efforts at good health turn out to be futile. The futility for Renton seems tied to his drug use and his friends—he actually finds some happiness in London when working in real estate, indicating that quitting heroin and trying to be productive might not be a futile pursuit.
Destiny and yearning (motif)
A sense of yearning for something greater is central to Renton’s psyche, as well as the psyche of some of his friends. This idea that he is destined for something greater is one of the key ways in which he is compared with Sick Boy, and it draws out their similarities. It seems to be a part of Begbie’s characterization as well, and each character’s secret belief that they are destined for greatness likely underlies much of their selfish behavior toward their friends. This characterization of Renton is particularly important for understanding his motives—it drives his repeated decisions to try to quit heroin and make something of himself, and it undermines his attempt to portray himself as completely nihilistic at the start of the film. In the end, a yearning to be free of the negative influence of his friends and start over drives his final decision to steal from them and run away.
