What is the management of diverticular (diverticulum-related) bleed?

Management of Diverticular Bleeding

Diverticular bleeding requires immediate resuscitation targeting hemoglobin >7 g/dL (7-10 g/dL range), followed by urgent colonoscopy within 12-24 hours after hemodynamic stabilization and rapid bowel preparation for both diagnosis and endoscopic therapy. 1

Initial Resuscitation and Stabilization

Transfuse red blood cells to maintain hemoglobin >7 g/dL, targeting the 7-10 g/dL range in all patients with diverticular bleeding. 1 This restrictive transfusion strategy improves outcomes compared to liberal approaches. 2

• Maintain mean arterial pressure >65 mmHg while avoiding fluid overload, as excessive volume can worsen bleeding. 1
• Monitor hourly urine output targeting >30 mL/hour in severe cases. 1
• Correct coagulopathy early: interrupt warfarin at presentation and use prothrombin complex concentrate for unstable hemorrhage. 2
• Resuscitate with crystalloids (normal saline or lactated Ringer's solution) before packed red blood cell transfusion. 3

Critical pitfall: Up to 11-15% of presumed lower GI bleeds are actually upper GI sources, particularly with brisk rectal bleeding, hemodynamic compromise, or elevated BUN/creatinine ratio. 2 Consider upper endoscopy if colonoscopy fails to identify a source.

Diagnostic Approach

Stable Patients (Shock Index ≤1)

Perform urgent colonoscopy within 12-24 hours after hemodynamic stabilization. 1 This is the primary diagnostic and therapeutic modality for diverticular bleeding. 3, 4

• Administer rapid bowel preparation with 4-6 liters of polyethylene glycol solution over 3-4 hours before colonoscopy. 1
• Use CO2 insufflation to reduce gas explosion risk in poorly prepared colons. 1
• Colonoscopy identifies the bleeding source and allows immediate therapeutic intervention in the same session. 5

Unstable Patients (Shock Index >1) or Active Bleeding

Perform CT angiography as the first-line investigation in unstable patients or those with ongoing severe bleeding. 2 CTA is faster and safer than colonoscopy in this setting and can identify non-colonic sources. 2

• If CTA shows no source in unstable patients, perform upper endoscopy immediately, as 11-15% have upper GI bleeding. 2
• If CTA is positive, proceed directly to catheter angiography with embolization within 60 minutes for unstable patients. 2
• Radionuclide scanning (technetium-99m-tagged red blood cell scan) can be used if colonoscopy and CTA are non-diagnostic, though it has low spatial resolution. 3, 4

Endoscopic Treatment

Endoscopic therapy should be performed when the bleeding diverticulum is identified during colonoscopy. 1 Multiple therapeutic options are available:

• Endoscopic band ligation shows superior outcomes with lower early rebleeding rates (6%) compared to clipping (33%). 1
• Other effective options include endoscopic clipping, injection therapy (epinephrine), thermal therapies, and hemostatic powders. 1, 3
• Use dual modality therapy (epinephrine injection plus one other method) when possible, extrapolating from upper GI ulcer bleeding evidence. 2
• Over-the-scope clip (OTSC) method is effective for severe diverticular bleeding, especially in cases of rebleeding after first-line conventional endoscopic procedures. 6

Important consideration: Approximately 70-80% of diverticular bleeding stops spontaneously, but endoscopic therapy reduces early rebleeding rates. 3, 5

Angiographic Intervention

Consider angiography when endoscopic visualization or treatment fails, or when there is ongoing severe bleeding with hemodynamic instability. 1

• Technical success rates for embolization are 93-100% regardless of embolic agent used. 1
• Angiography requires active bleeding rates >0.5 mL/min to localize the bleeding site. 7
• Selective angiographic embolization achieves immediate hemostasis in 40-100% of cases with rebleeding rates around 15%. 7
• Risk of bowel ischemia following embolization is 1-4%. 7

Surgical Management

Surgery is indicated for patients with ongoing bleeding despite endoscopic and angiographic interventions, or for those with recurrent severe diverticular bleeding episodes. 1

• Segmental colectomy is the preferred surgical option when the bleeding source is localized, with mortality rates of 5-10% and rebleeding rates of 14% at 1 year. 1
• Subtotal colectomy is necessary when localization is not possible preoperatively. 4
• Critical pitfall: Do not perform emergency laparotomy without exhaustive radiologic and endoscopic localization attempts, as operative mortality is approximately 10%. 2
• Intraoperative colonoscopy can facilitate accurate identification of pathology when the bleeding source remains undetected. 8

Specific surgical indications include:

• Hemodynamic instability persisting despite resuscitation 2
• Transfusion requirement exceeding 6 units 2
• Severe bleeding recurrence 2

Risk Factors for Rebleeding

History of prior diverticular bleeding, chronic kidney disease, and failure to identify and treat the bleeding point are key risk factors for rebleeding. 1

• Approximately 18-53% of patients may require emergency surgery if bleeding recurs. 6
• About 50% of patients with diverticular bleeding require blood transfusion. 6
• Endoscopic therapy significantly reduces rebleeding risk when the source is identified and treated. 5

Management Algorithm Summary

1. Immediate resuscitation: Target Hb >7 g/dL, MAP >65 mmHg 1
2. Risk stratification: Assess shock index and hemodynamic stability 2
3. Stable patients: Urgent colonoscopy within 12-24 hours after bowel preparation 1
4. Unstable patients: CT angiography first, then angiographic embolization or upper endoscopy as indicated 2
5. Endoscopic hemostasis: Band ligation preferred, or dual modality therapy 1, 2
6. Failed endoscopy: Angiographic embolization 1
7. Failed medical/interventional therapy: Surgical resection 1