Lower gastrointestinal bleeding (LGIB) is a common clinical emergency. However, most of the published findings on LGIB were of retrospective or observational studies, and the relevant clinical guidelines and consensuses were not published until quite recently. In clinical practice, LGIB treatment is not as standardized as the treatment of upper gastrointestinal bleeding. Herein, on the basis of the latest clinical research findings on and guidelines for LGIB, we summarized and analyzed the existent diagnosis and treatment of LGIB from the perspectives of patient assessment and endoscopic, interventional and medication treatment, intending to provide more references to support the clinical practice.

This is the first UK national guideline to concentrate on acute lower gastrointestinal bleeding (LGIB) and has been commissioned by the Clinical Services and Standards Committee of the British Society of Gastroenterology (BSG). The Guidelines Development Group consisted of representatives from the BSG Endoscopy Committee, the Association of Coloproctology of Great Britain and Ireland, the British Society of Interventional Radiology, the Royal College of Radiologists, NHS Blood and Transplant and a patient representative. A systematic search of the literature was undertaken and the quality of evidence and grading of recommendations appraised according to the GRADE(Grading of Recommendations Assessment, Development and Evaluation) methodology. These guidelines focus on the diagnosis and management of acute LGIB in adults, including methods of risk assessment and interventions to diagnose and treat bleeding (colonoscopy, computed tomography, mesenteric angiography, endoscopic therapy, embolisation and surgery). Recommendations are included on the management of patients who develop LGIB while receiving anticoagulants (including direct oral anticoagulants) or antiplatelet drugs. The appropriate use of blood transfusion is also discussed, including haemoglobin triggers and targets.