Preprocedural CT-guided anatomical assessment shortens intubation time and improves patient and operator experience during unsedated colonoscopy: a randomised controlled trial

Looping is a major cause of difficult and painful insertion during unsedated colonoscopy, yet strategies are largely guided by trial and error; prolonged insertion may jeopardise completion, discourage future surveillance and is associated with lower adenoma detection. In this randomised trial of 141 patients, protocolised review of pre-existing abdominal-pelvic computed tomography (CT) anticipated colonic anatomy and shortened caecal intubation time by 136 s, while reducing pain, discomfort and operator workload and increasing willingness to repeat colonoscopy. Effects were largest in N-loop and alpha-loop configurations, which accounted for 83% of patients. Routinely acquired CT could support anatomy-informed colonoscope insertion especially when anesthesia services are limited or sedation poses an elevated risk.