One of the film’s most memorable moments involves McGregor’s character, Mark Renton, diving into what is described as “Scotland’s dirtiest toilet” to retrieve drugs. Welsh confirmed that this infamous scene will be recreated in the musical adaptation at London’s Haymarket Theatre.

To prepare for this iconic role, a 24-year-old McGregor immersed himself in the world of Scottish drug users. For the unforgettable toilet scene, he had to crawl through a set that was filled with chocolate rather than actual filth, creating a legendary moment in film history.

One of its most infamous scenes saw Ewan’s character Mark Renton crawl into ‘Scotland’s dirtiest toilet’ to recover drugs, which the writer said will feature in the musical adaption at London’s Haymarket Theatre. 

The actor, then 24, met Scottish drug addicts to prepare for the role and even had to tunnel his way through the public toilet and burst out from the basin, filled with chocolate rather than faeces for the now legendary scene. 

Teasing how the moment will be achieved on stage, Welsh said: ‘We’ll be using lots of film stuff you’ll see an interesting multimedia approach’. 

‘I’m not gonna say there’s gonna be a lot of s**t flying around the theatre, but maybe there will be’.

A musical version of iconic 90s film Trainspotting will open in London’s West End this summer its writer Irvine Welsh has announced – 30 years after the movie’s release

The writer said that the theme of addiction could not be more timely with so many people compulsion for social media and doom scrolling. 

He also hit back at suggestions that the movie’s themes were too dark and distressing to be made into a musical.

Telling The Sun: ‘Musicals are traditionally quite dark ways of storytelling, You’ve got a lot of musicals that deal with social issues, like Rent and West Side Story. Oliver is about destitute children so you have a tradition of being able to look at sometimes very difficult material’. 

Trainspotting was Boyle’s first major hit following 1994’s Shallow Grave, and helped catapult Ewan McGregor to stardom.

Despite falling out with the director over his decision to cast Leonardo Di Caprio in his 2000 film The Beach, the pair reconciled for the sequel. 

The Academy Award-nominated screenplay by John Hodge followed the group of heroin addicts around Edinburgh through urban poverty and squalor.

Based on his 1993 novel, the film, which made stars of Ewan McGregor and Kelly Macdonald as well its director Danny Boyle , followed a group of Edinburgh heroin addicts

The novel was longlisted for the 1993 Booked Prize, reportedly not making it any further because its content offended two judges.

The film made £12 million in the UK and £46.79 million internationally despite only costing £1.6 million to make.

Filming was so low-budget most scenes were done in one take and the cast and crew worked out of an abandoned cigarette warehouse in Glasgow.

The movie’s sequel, which was released in 2017, was based on Welsh’s follow-up book, Porno.

The sequel is set ten years after Trainspotting and sees the characters cross paths again, but with an alternative gritty backdrop of the pornography business, rather than heroin use.