What should be done if there is blood in the stool?

Management of Blood in Stool

Blood in stool requires prompt evaluation with endoscopy as the initial diagnostic procedure, starting with upper GI endoscopy followed by colonoscopy within 24 hours, regardless of the suspected bleeding source. 1

Initial Assessment and Triage

• First steps based on clinical presentation:

  • Assess hemodynamic stability (vital signs, hemoglobin, hematocrit)
  • Determine severity of bleeding (amount, color, frequency)
  • Perform digital rectal examination to rule out anorectal causes 2, 1

• Hemodynamic status determines urgency:

  • Unstable patients (shock, persistent hypotension): Immediate resuscitation and surgical consultation 2
  • Stable patients with active bleeding: Urgent evaluation within 24 hours
  • Stable patients with intermittent/minimal bleeding: Expedited outpatient evaluation

Diagnostic Algorithm

1. Initial resuscitation (if needed):

   • IV fluid/blood product resuscitation
   • Maintain hemoglobin >7g/dL (>9g/dL in patients with cardiovascular disease) 2

2. Upper GI endoscopy first:

   • Essential even with suspected lower GI bleeding
   • 10-15% of severe hematochezia cases have upper GI sources 1
   • Negative nasogastric tube aspirate does not rule out upper GI source 1

3. Lower GI evaluation:

   • Colonoscopy within 24 hours after adequate bowel preparation 1
   • Rapid purge with polyethylene glycol solutions (4-6L over 3-4 hours) 1

4. If bleeding persists and endoscopy is non-diagnostic:

   • CT angiography (detects bleeding at rates of 0.3-1.0 mL/min) 1
   • Consider direct angiography for both diagnosis and intervention 1

Specific Management Based on Findings

• Diverticular bleeding:

  • Endoscopic treatment with clips, thermal therapy, or injection
  • Angiographic embolization if endoscopy fails

• Angiodysplasia:

  • Endoscopic treatment with argon plasma coagulation or thermal therapy

• Inflammatory bowel disease:

  • Medical management of underlying disease
  • Surgical intervention for massive hemorrhage unresponsive to medical therapy 2

• Hemorrhoids:

  • Conservative management for thrombosed hemorrhoids (topical treatments)
  • Consider surgical excision based on local expertise and patient preference 2

• Neoplasms:

  • Biopsy and staging
  • Endoscopic or surgical intervention based on findings

Indications for Surgical Intervention

Surgery is indicated in the following scenarios 2, 1:

• Life-threatening bleeding with persistent hemodynamic instability
• Non-response to resuscitation efforts
• Requirement of >6 units of blood transfusion
• Recurrent severe bleeding after endoscopic or angiographic interventions

Common Pitfalls and Caveats

1. Delayed upper endoscopy can lead to missed diagnoses of upper GI sources, even in cases of suspected lower GI bleeding 1

2. Medication-related bleeding is common, especially in older adults:

   • NSAIDs, antiplatelet agents, and anticoagulants increase bleeding risk 3
   • Consider temporary discontinuation of these medications in consultation with specialists

3. Occult bleeding presenting as iron deficiency anemia requires thorough evaluation:

   • Start with colonoscopy, then upper endoscopy if negative 4
   • Consider small bowel evaluation if both are negative

4. Combined antiplatelet therapy or antiplatelet plus anticoagulant therapy significantly increases bleeding risk compared to monotherapy 3

5. Failure to recognize rapid bleeding can lead to delayed intervention and worse outcomes

Follow-up Recommendations

• Outpatient follow-up within 2 weeks for patients discharged after minor bleeding 1
• Iron supplementation for patients with anemia 1
• Age-appropriate cancer screening 1
• Optimization of underlying disease treatment (e.g., Crohn's disease) 1

By following this structured approach to evaluating blood in stool, clinicians can efficiently diagnose the source of bleeding and provide appropriate treatment to reduce morbidity and mortality.