Management of Anticoagulant-Associated Lower GI Bleeding
For patients with anticoagulant-associated lower GI bleeding, interrupt the anticoagulant immediately; if hemodynamically unstable or life-threatening hemorrhage, reverse warfarin with prothrombin complex concentrate (PCC) plus vitamin K, but do NOT routinely use reversal agents for DOACs. 1
Initial Anticoagulant Management by Drug Type
Warfarin
- Interrupt warfarin at presentation for all patients with lower GI bleeding 1
- For low-risk hemorrhage: simple discontinuation is sufficient (warfarin has 3-5 day half-life) 1
- For severe/unstable hemorrhage: give four-factor prothrombin complex concentrate (PCC) plus vitamin K 5-10 mg IV 1
- The 2022 ACG/CAG guideline suggests against giving fresh frozen plasma or vitamin K for acute GI bleeding, but if reversal is needed, PCC is preferred over fresh frozen plasma 2
- Do NOT use fresh frozen plasma as first-line (PCC is superior) 1, 2
Direct Oral Anticoagulants (DOACs)
- Discontinue the DOAC immediately 1
- Do NOT routinely give PCC for DOAC-associated bleeding 1, 2
- Do NOT routinely use specific reversal agents (idarucizumab for dabigatran, andexanet alfa for rivaroxaban/apixaban) in the acute GI bleeding setting 1, 2
- The 2025 Association of Anaesthetists guideline states these agents should be reserved for emergency surgery/procedures where bleeding risk is significant, NOT routine GI bleeding 1
- Andexanet alfa carries 10% thrombotic event risk within 30 days and 18% overall thromboembolic event rate 3
- The 2022 ACG/CAG guideline specifically recommends against these reversal agents for acute GI bleeding 2
Unfractionated Heparin
- Discontinuation alone is usually adequate (short half-life) 1
- For severe life-threatening hemorrhage: reverse with protamine sulfate 1
Low Molecular Weight Heparin
- Anticoagulant effect persists 24 hours 1
- Protamine sulfate is less effective than for unfractionated heparin 1
Supportive Management
Transfusion Strategy
- Use restrictive RBC transfusion thresholds: Hb trigger 70 g/L, target 70-90 g/L 1
- Exception: patients with cardiovascular disease should have trigger 80 g/L, target up to 100 g/L 1
- Over 80% of transfusions in lower GI bleeding may be inappropriate or unnecessary 1
Coagulopathy Correction
- Correct INR >1.5 with fresh frozen plasma 1
- Correct thrombocytopenia <50,000/µL with platelet transfusion 1
Timing of Anticoagulation Resumption
Warfarin - Low Thrombotic Risk
- Restart warfarin at 7 days after lower GI bleeding 1
- Restarting between 7-15 days reduces thromboembolic events and mortality without increasing rebleeding 1
- Starting before 7 days results in twofold increase in rebleeding 1
High Thrombotic Risk Patients
High thrombotic risk includes: prosthetic metal mitral valve, atrial fibrillation with prosthetic valve or mitral stenosis, <3 months after venous thromboembolism 1
- Consider low molecular weight heparin bridging at 48 hours after hemostasis is achieved 1
- This applies to both warfarin and DOAC patients with high thrombotic risk 1
Critical Pitfalls to Avoid
- Do NOT routinely use DOAC reversal agents (idarucizumab, andexanet alfa) for acute GI bleeding - these carry significant thrombotic risk and are not recommended by current guidelines 1, 3, 2
- Do NOT use fresh frozen plasma for warfarin reversal if PCC is available - PCC is more effective 1, 2
- Do NOT restart warfarin before 7 days - doubles rebleeding risk 1
- Do NOT give platelet transfusions for antiplatelet-associated bleeding 2
- Most lower GI bleeding stops spontaneously (80% of cases), so aggressive reversal may cause more harm than benefit through thrombotic complications 1
Diagnostic Approach
- Colonoscopy is required in patients bleeding on anticoagulants to identify the source 4
- Anticoagulant use does not preclude endoscopic intervention 1
- Common causes: diverticular disease (most common), vascular ectasias, polyps/neoplasia 1, 4, 5
- Colon cancer is more common in anticoagulated patients with lower GI bleeding (10.2% vs 3.2% in non-anticoagulated) 1, 4