What is the management approach for a patient with a lower gastrointestinal (GI) bleed?

From the Guidelines

The management of a lower gastrointestinal (GI) bleed should prioritize patient stabilization, followed by diagnosis and definitive treatment, with colonoscopy being the primary diagnostic tool, as recommended by the British Society of Gastroenterology 1. The approach to managing a lower GI bleed involves several key steps, including:

• Assessing hemodynamic stability with vital signs and establishing large-bore IV access for fluid resuscitation using crystalloids like normal saline or lactated Ringer's.
• Blood transfusion with packed red blood cells is indicated for hemoglobin below 7 g/dL or for unstable patients, with restrictive RBC thresholds (Hb trigger 70 g/L and a Hb concentration target of 70–90 g/L after transfusion) being recommended, unless the patient has a history of cardiovascular disease, in which case a trigger of 80 g/L and a target of 100 g/L should be used 1.
• Correcting any coagulopathy with fresh frozen plasma, platelets, or reversal agents as needed, and interrupting warfarin therapy at presentation, with anticoagulation being reversed with prothrombin complex in cases of unstable gastrointestinal haemorrhage 1.
• After stabilization, performing diagnostic evaluation including a focused history, physical examination, and laboratory tests (complete blood count, coagulation studies, and type and cross).
• Colonoscopy is the primary diagnostic tool for lower GI bleeding and should be performed after adequate bowel preparation when the patient is stable, ideally within 24 hours of presentation, as recommended by the British Society of Gastroenterology 1 and supported by the American College of Radiology 1.
• For massive bleeding, CT angiography can identify the bleeding source, followed by interventional radiology for embolization if needed, with transcatheter arteriography/embolization being usually appropriate as the next intervention for a patient with ongoing or recurrent lower GIB where appropriate colonoscopy has localized the bleeding site and treatment was attempted 1.
• Specific treatments depend on the cause, with diverticular bleeding often stopping spontaneously but may require endoscopic hemostasis, angiodysplasia being treated with endoscopic coagulation, hemorrhoids with banding or sclerotherapy, and inflammatory bowel disease with appropriate medical therapy.
• Surgery is reserved for cases refractory to other interventions, with no patient proceeding to emergency laparotomy unless every effort has been made to localize bleeding by radiological and/or endoscopic modalities, except under exceptional circumstances 1.

From the Research

Management Approach for Lower GI Bleed

The management approach for a patient with a lower gastrointestinal (GI) bleed involves several steps, including:

• Initial assessment of the patient's history, co-morbidities, medications, hemodynamic parameters, physical examination, and laboratory markers 2
• Use of a risk score to aid in clinician judgment, but not replace it 2
• Consideration of a restrictive red blood cell transfusion strategy in hemodynamically stable patients with no history of cardiovascular disease, with a hemoglobin threshold of ≤ 7 g/dL prompting red blood cell transfusion 2
• Consideration of a more liberal red blood cell transfusion strategy in hemodynamically stable patients with a history of acute or chronic cardiovascular disease, with a hemoglobin threshold of ≤ 8 g/dL prompting red blood cell transfusion 2

Diagnostic Testing

Diagnostic testing for lower GI bleed includes:

• Colonoscopy, which should be performed sometime during the patient's hospital stay, but not necessarily as an urgent procedure 2, 3, 4
• Computed tomography angiography (CTA) in patients with suspected ongoing bleeding or hemodynamic instability 2, 3, 5
• Technetium Tc 99m-labeled red blood cell scintigraphy, which should not be routinely used in the evaluation of lower GI bleeding 5

Management of Antithrombotic Medications

The management of antithrombotic medications in patients with lower GI bleed includes:

• Withholding vitamin K antagonists and correcting coagulopathy according to the severity of bleeding and thrombotic risk 2
• Temporarily withholding direct oral anticoagulants at presentation 2
• Not withholding aspirin in patients taking low-dose aspirin for secondary cardiovascular prevention, and resuming it within 5 days if hemostasis is achieved or there is no further evidence of bleeding 2
• Not routinely discontinuing dual antiplatelet therapy before cardiology consultation, but considering continuation or temporary interruption according to the severity of bleeding and ischemic risk 2