What is the initial approach for treating lower gastrointestinal (GI) bleeding?

Initial Treatment of Lower Gastrointestinal Bleeding

For hemodynamically unstable patients (shock index >1), immediately perform CT angiography to localize bleeding, followed by catheter angiography with embolization within 60 minutes; for stable patients, calculate the Oakland score—those with ≤8 points can be discharged for urgent outpatient workup, while those with >8 points require hospital admission for colonoscopy within 24 hours. 1

Immediate Hemodynamic Assessment and Resuscitation

Assess shock index first (heart rate divided by systolic blood pressure)—a value >1 indicates hemodynamic instability requiring urgent intervention 1, 2. This takes priority over all other assessments.

• Place at least two large-bore IV catheters immediately for rapid volume expansion 2
• Initiate crystalloid fluid resuscitation to restore hemodynamic stability 2
• Perform digital rectal examination to confirm blood in stool and exclude anorectal pathology 3
• Check for orthostatic hypotension, which indicates significant blood loss requiring ICU admission 3

Risk Stratification for Hemodynamically Stable Patients

Use the Oakland score to guide disposition decisions, which includes: age, gender, previous LGIB admission, digital rectal examination findings, heart rate, systolic blood pressure, and hemoglobin level 1.

• Oakland score ≤8 points: Safe for discharge with urgent outpatient investigation 1
• Oakland score >8 points: Requires hospital admission for colonoscopy 1

Management Based on Hemodynamic Status

Hemodynamically Unstable Patients (Shock Index >1)

CT angiography is the immediate first-line test—it provides the fastest, least invasive means to localize active bleeding 1, 2. Do not delay for colonoscopy preparation in unstable patients.

• Following positive CTA, proceed directly to catheter angiography with embolization within 60 minutes in centers with 24/7 interventional radiology 1, 2
• Critical pitfall: Always consider an upper GI source in hemodynamically unstable patients presenting with hematochezia—perform upper endoscopy if suspicion exists 2, 4
• If patient remains unstable despite aggressive resuscitation, proceed directly to surgery 3, 2

Hemodynamically Stable Patients

Colonoscopy is the initial diagnostic and therapeutic procedure and should be performed within 24 hours after adequate bowel preparation 1, 4.

• Endoscopic hemostasis should be provided for high-risk stigmata: active bleeding, non-bleeding visible vessel, or adherent clot 4
• Hemostasis modalities include mechanical, thermal, injection, or combination therapy based on bleeding etiology and endoscopist experience 4

Transfusion Management

Use restrictive transfusion thresholds for most clinically stable patients 1, 2:

• Without cardiovascular disease: Hemoglobin trigger 70 g/L (7 g/dL), target 70-90 g/L 1, 2
• With cardiovascular disease: Hemoglobin trigger 80 g/L (8 g/dL), target ≥100 g/L 1, 2

Coagulopathy Correction

Correct coagulopathy immediately if present 3:

• INR >1.5: Transfuse fresh frozen plasma 3
• Platelets <50,000/µL: Transfuse platelets 3

Anticoagulation Management

For patients on warfarin with unstable GI hemorrhage 1, 2:

• Interrupt warfarin immediately at presentation 1
• Reverse anticoagulation with prothrombin complex concentrate AND vitamin K 1, 2
• For patients with low thrombotic risk, restart warfarin 7 days after hemorrhage 1, 2

Antiplatelet Management

Aspirin management depends on indication 1:

• Primary prophylaxis: Permanently discontinue aspirin 1
• Secondary prevention: Do NOT routinely stop aspirin; if stopped, restart as soon as hemostasis is achieved 1, 4

ICU Admission Criteria

Admit to ICU if any of the following 3:

• Orthostatic hypotension present 3
• Hematocrit decrease ≥6% 3
• Transfusion requirement >2 units packed red blood cells 3
• Continuous active bleeding 3
• Persistent hemodynamic instability despite aggressive resuscitation 3

Critical Pitfalls to Avoid

• Missing an upper GI source: Up to 15% of patients with hematochezia have upper GI bleeding—always consider this in unstable patients 2, 4
• Delaying intervention in unstable patients: Do not attempt colonoscopy preparation in shock index >1 patients—proceed directly to CTA 1
• Underestimating mortality risk: Mortality is generally related to comorbidity rather than exsanguination, with in-hospital mortality of 3.4% overall but rising to 18% for inpatient-onset LGIB and 20% for patients requiring ≥4 units of red cells 1
• Inappropriate anticoagulation management: Anticoagulant use does not preclude endoscopic intervention, but unstable hemorrhage requires immediate reversal 3, 1

Recurrent or Ongoing Bleeding

If bleeding continues despite initial management 4:

• Consider repeat colonoscopy with endoscopic hemostasis 4
• Proceed to angiographic embolization if endoscopy fails 1
• Surgery is indicated when active bleeding from a segmental lesion amenable to surgical cure persists despite other interventions 1