ACR Appropriateness Criteria® Radiologic Management of Lower Gastrointestinal Tract Bleeding: 2021 Update

Diverticulosis remains the commonest cause for acute lower gastrointestinal tract bleeding (GIB). Conservative management is initially sufficient most patients, followed by elective diagnostic tests. However, if GIB persists, it can be investigated with colonoscopy, CT angiography (CTA), or red blood cell (RBC) scan. Colonoscopy identify site and of provide effective treatment. CTA a noninvasive tool that better tolerated actively potential lesion in vast majority patients. RBC scan intermittent bleeding, single-photon emission computed tomography, more accurately localize to small segment bowel. If patients are hemodynamically unstable, transcatheter arteriography/embolization performed. also considered these rapid bowel preparation feasible. Transcatheter arteriography has low rate major complications; however, targeted embolization only feasible extravasation seen, which likely unstable been previously localized but intervention colonoscopy have failed achieve hemostasis, surgery may required. Among obscure (nonlocalized) recurrent capsule endoscopy enterography culprit mucosal lesion(s).The American College Radiology Appropriateness Criteria evidence-based guidelines specific clinical conditions reviewed annually multidisciplinary expert panel. The guideline development revision include an extensive analysis current medical literature from peer journals application well-established methodologies (RAND/UCLA Method Grading Recommendations Assessment, Development, Evaluation GRADE) appropriateness imaging treatment procedures scenarios. In those instances where evidence lacking equivocal, opinion supplement available recommend