In the UK in 2002, colorectal surgeons and gastroenterologists came up with guidelines recommending when colonoscopy needed to be done. When the characteristics of patients on the waiting list for colonoscopy in one district hospital were examined, only 24% were kept on the waiting list. As a result of implementing the guidelines, waiting times for diagnostic colonoscopy fell from 12 to 4 weeks for urgent and from 40 to 15 weeks for routine referrals.
A. Shoaib, A Hamade, A Zia, PS Basnyat and N. Taffinder. “Why wait for a colonoscopy? An easy cure.” Colorectal Disease. 2005: 8, 480-483.