[Diagnostic performance of colonoscopy in lower gastrointestinal bleeding]

Lower gastrointestinal bleeding is a common medical emergency that usually has a favorable prognosis. However, these events generate high resource use. The procedure of choice is colonoscopy with prior colonic preparation due to its high diagnostic performance and safety and the possibility of endoscopic therapy. Emergency colonoscopy has advantages over elective colonoscopy, showing higher diagnostic yield and superior detection of stigmata of recent bleeding, increasing the probability of endoscopic treatment. Predictive models of bleeding severity and recurrence have been published, allowing resource use to be rationalized, mainly by reducing hospital stay in low-risk patients. Nevertheless, the optimal timing of emergency colonoscopy has not been established and the impact of endoscopic treatment on prognosis is controversial.