What is the management and treatment approach for a patient presenting with harmatochezia (passage of fresh blood per anus)?

Management of Hematochezia (Passage of Fresh Blood Per Anus)

The management of hematochezia requires urgent colonoscopy within 24 hours of presentation after appropriate hemodynamic stabilization to diagnose and potentially treat the source of bleeding. 1, 2

Initial Assessment and Resuscitation

• Perform immediate hemodynamic assessment including vital signs, hemoglobin, hematocrit, and coagulation parameters to evaluate bleeding severity 1, 2
• Establish two large-bore venous access for fluid resuscitation and blood product administration 2
• For patients with severe bleeding, maintain hemoglobin level >7 g/dL and mean arterial pressure >65 mmHg while avoiding fluid overload 3, 2
• Provide intravenous fluid replacement and blood transfusions as necessary based on hemodynamic status 3, 1
• Correct any coagulopathy before invasive procedures 3, 1
• Insert urinary catheter to monitor hourly urine output (target >30 mL/hr) in severe cases 2
• Consider discontinuing antiplatelet agents temporarily during acute bleeding episodes 2

Diagnostic Approach

• After hemodynamic stabilization, urgent colonoscopy within 24 hours is the recommended first-line diagnostic approach 3, 1
• Ensure thorough bowel preparation to improve visualization, as poor preparation may lead to incomplete evaluation 1, 4
• Consider upper endoscopy to exclude an upper GI source of bleeding, especially in patients with hemodynamic instability, as 10-15% of patients with severe hematochezia have an upper GI source 3, 2
• For hemodynamically unstable patients or those with suspected active bleeding, CT angiography may be performed first to rapidly localize the bleeding site 2

Diagnostic Algorithm When Initial Colonoscopy is Inconclusive

• If initial colonoscopy is inconclusive but suggests bleeding around the ileocecal valve, perform repeat colonoscopy with thorough bowel preparation 4
• If repeat colonoscopy fails to identify the source, consider radionuclide imaging with [99Tcm] pertechnetate-labeled red blood cells, which can detect active bleeding at rates of 0.1-0.5 mL/min 1, 4
• Angiography should be performed only after positive scintigraphy or in patients with hemodynamic instability and severe unremitting bleeding 4
• Angiography requires a bleeding rate of at least 1 mL/min for accurate detection of extravasation 4

Therapeutic Interventions

• Endoscopic hemostasis is the preferred first-line treatment for accessible bleeding sources identified during colonoscopy 3, 5
• Multiple endoscopic techniques are available for controlling bleeding, including injection therapy, thermal coagulation, and mechanical methods such as clips 3
• For anorectal varices with mild bleeding, focus on optimal medication for portal hypertension along with supportive care 3
• For radiation proctitis causing bleeding, consider formalin application or sucralfate enemas 3
• Surgical intervention is required in approximately 1.3% of hematochezia cases, primarily for severe refractory bleeding 5
• Risk factors for requiring surgery include transfusion need ≥6 units, in-hospital rebleeding, small bowel bleeding, colorectal cancer, and hemorrhoids 5

Common Causes of Hematochezia

• Diverticular bleeding (most common cause of lower GI bleeding in adults) 1
• Angiodysplasia (most common in cecum and proximal ascending colon) 3, 4
• Hemorrhoids (common finding but may not always be the source of significant bleeding) 6
• Colorectal cancer and polyps (more common in older patients) 6, 7
• Inflammatory bowel disease and other forms of colitis 3
• Anorectal varices in patients with portal hypertension 3

Special Considerations

• Approximately 75% of episodes of acute lower GI bleeding due to diverticulosis stop spontaneously 1
• In patients with severe hematochezia and hypovolemia, consider an upper GI source even when presentation suggests lower GI bleeding 3
• Nasogastric lavage before upper endoscopy is warranted if there is medium to low suspicion of an upper GI source 3
• For patients with radiation proctitis causing recurrent bleeding, endoscopic treatment with argon plasma coagulation or application of formalin may be effective 3

Common Pitfalls to Avoid

• Delaying resuscitation to perform diagnostic procedures; stabilization takes priority 2
• Inadequate bowel preparation leading to poor visualization during colonoscopy 4
• Over-transfusion, which may increase portal pressure and potentially worsen bleeding in patients with portal hypertension 3, 2
• Premature resort to surgery without attempting to localize bleeding through radiological and/or endoscopic modalities first 2, 5
• Assuming hemorrhoids are the source of bleeding without excluding more proximal sources 6