What is the treatment approach for a patient presenting with hematochezia (blood in stool)?

Treatment of Blood in Stool (Hematochezia)

Immediately assess hemodynamic stability and begin resuscitation with IV fluids and blood products while simultaneously determining the bleeding source through CT angiography in unstable patients or colonoscopy in stable patients, with surgery reserved for those with hemorrhagic shock non-responsive to resuscitation or life-threatening hemorrhage. 1

Immediate Hemodynamic Assessment and Resuscitation

The first critical step is determining hemodynamic stability, which dictates your entire management pathway:

• Calculate the shock index (heart rate divided by systolic blood pressure)—a value <1 defines hemodynamic stability 1
• Check vital signs, measure hemoglobin/hematocrit, and assess coagulation parameters immediately 1, 2
• Obtain blood typing and cross-matching for severe bleeding 1, 2

Resuscitation Protocol

• Begin IV fluid and blood product resuscitation immediately to normalize blood pressure and heart rate 1, 2
• Transfuse packed red blood cells to maintain hemoglobin >7 g/dL (use 9 g/dL threshold if massive bleeding, cardiovascular comorbidities, or anticipated delay in intervention) 3, 1
• Interrupt warfarin at presentation 1

Critical pitfall: Approximately 20% of patients requiring ≥4 units transfusion have significant mortality risk 1, 2

Diagnostic and Therapeutic Algorithm Based on Hemodynamic Status

For Hemodynamically Unstable Patients (Shock Index ≥1):

• Perform CT angiography as the first-line investigation before endoscopy—CTA detects bleeding at rates as low as 0.3 mL/min 1, 4
• Proceed to immediate surgery if patient remains non-responsive to resuscitation 3, 1
• Do not delay CTA or surgery in unstable patients 1, 4

For Hemodynamically Stable Patients (Shock Index <1):

• Perform colonoscopy within 24 hours after adequate colon preparation as the initial diagnostic and therapeutic procedure 5
• Upper and lower GI endoscopy should be the initial diagnostic procedures to exclude upper GI sources 3, 4
• Anoscopy or proctoscopy should be performed first to identify common anorectal causes (hemorrhoids, fissures) 4

Critical pitfall: Do not assume upper GI sources are excluded based on bright red blood alone—hematochezia with hemodynamic instability may indicate an upper GI source 5

Endoscopic Hemostasis

When colonoscopy identifies a bleeding source:

• Provide endoscopic hemostasis for high-risk stigmata: active bleeding, non-bleeding visible vessel, or adherent clot 5
• Use mechanical therapy (clips, band ligation), thermal coagulation, injection therapy, or combination approaches based on bleeding etiology and lesion accessibility 3, 5
• Endoscopic hemostasis significantly reduces surgery rates (e.g., for small bowel bleeding: 2% with hemostasis vs 12% without) 6

Surgical Indications

Surgery is indicated immediately in the following scenarios:

• Hemorrhagic shock non-responsive to resuscitation 3, 1
• Free perforation or generalized peritonitis 3, 1
• Massive hemorrhage with increasing transfusion requirements 3, 1
• Life-threatening bleeding with persistent hemodynamic instability 3, 1
• Significant recurrent gastrointestinal bleeding 3, 1

Special Context: Inflammatory Bowel Disease

For patients with acute severe ulcerative colitis (≥6 bloody stools daily plus tachycardia >90 bpm, fever >37.8°C, anemia <10.5 g/dL, or ESR >30 mm/h):

• Subtotal colectomy with ileostomy is the surgical treatment of choice for life-threatening hemorrhage non-responsive to medical therapy 3, 1
• Do not delay surgery beyond 48-72 hours if no improvement or deterioration occurs, as perforation carries 27-57% mortality 3, 1
• Approximately 66% respond to steroids; 34% require colectomy 1

Alternative Diagnostic Modalities

If colonoscopy fails or cannot be performed:

• Angiography for active bleeding that cannot be localized endoscopically, with potential for therapeutic embolization 7, 5
• Tagged red blood cell scintigraphy for intermittent or slow bleeding when other methods fail 7, 5
• Repeat colonoscopy with endoscopic hemostasis for evidence of recurrent bleeding 5

Important consideration: Emergency visceral angiography has only 14% diagnostic yield compared to urgent colonoscopy, though the examinations may be complementary 8

Post-Treatment Management

• Avoid NSAID use in patients with history of acute lower GI bleeding, particularly if secondary to diverticulosis or angioectasia 5
• Do not stop aspirin therapy in patients with established high-risk cardiovascular disease (secondary prophylaxis)—timing of resumption depends on bleeding severity, adequacy of hemostasis, and thromboembolic risk 5
• Increase fiber and water intake for patients with IBD-related bleeding 1