23-year-old Dan Parker is one of the lucky ones - though he nearly lost the use of his bladder he is now, thankfully, on the road to recovery. "At the highest point I couldn't hold more than four to six millilitres of water in my bladder," he told ITV News. "I had letters off consultants and doctors saying that if I didn't stop I'd be using a colostomy bag." Dan is one of a growing number of young people suffering irreversible bladder failure after comparatively short periods of ketamine abuse. • Subscribe to ITV News on YouTube: http://bit.ly/2lOHmNj • Get breaking news and more stories at http://www.itv.com/news Follow ITV News on Facebook: https://www.facebook.com/itvnews/ Follow ITV News on Twitter: https://twitter.com/itvnews Follow ITV News on Instagram: https://www.instagram.com/itvnews/