What should I do for a patient with bright red rectal bleeding?

Management of Bright Red Rectal Bleeding

For patients with bright red rectal bleeding, perform direct anorectal inspection first, followed by CT angiography if hemodynamically unstable, or colonoscopy if stable, to identify the bleeding source and guide appropriate treatment. 1

Initial Assessment and Stabilization

• Assess hemodynamic status immediately by checking vital signs, determining hemoglobin/hematocrit levels, and evaluating coagulation parameters to determine bleeding severity 1
• For hemodynamically unstable patients (shock index >1), prioritize resuscitation with intravenous fluids while avoiding fluid overload, and maintain hemoglobin >7 g/dL 1
• Perform blood typing and cross-matching if severe bleeding is present 1
• Bright red rectal bleeding may indicate an anorectal source but can also represent more proximal bleeding, including upper GI sources 1

Diagnostic Approach Based on Hemodynamic Status

For Hemodynamically Unstable Patients:

• Perform CT angiography (CTA) as the first-line investigation to rapidly localize the bleeding site without requiring bowel preparation 1
• CTA has high sensitivity (79-95%) and specificity (95-100%) for detecting active bleeding, especially when the bleeding rate is 0.3-1.0 mL/min 1
• If CTA does not identify a bleeding source, perform immediate upper endoscopy to exclude an upper GI source, as up to 15% of patients with hematochezia may have upper GI bleeding 1

For Hemodynamically Stable Patients:

• Begin with direct anorectal examination (anoscopy/proctoscopy) to identify common anorectal causes such as hemorrhoids or fissures 1
• Even when an anorectal cause is identified, proceed with full colonoscopic evaluation, as studies show that 6-52% of patients with bright red rectal bleeding and hemorrhoids may have concurrent significant proximal pathology 2, 3
• Consider upper endoscopy if colonoscopy is negative, as 8-15% of patients with hematochezia may have an upper GI source 1, 4

Special Considerations

• For suspected anorectal varices, consider endoscopic ultrasound with color Doppler evaluation as a second-line diagnostic tool 1
• If endoscopic investigations and CTA are inconclusive, consider additional imaging such as nuclear medicine studies (red cell scintigraphy) or video capsule endoscopy 1
• For patients with inflammatory bowel disease presenting with rectal bleeding, sigmoidoscopy and esophagogastroduodenoscopy are recommended as first-line evaluations 1

Common Pitfalls to Avoid

• Do not assume that visible hemorrhoids are the definitive source of bleeding without further evaluation, as significant proximal pathology may coexist 2, 3, 4
• Do not delay CTA in hemodynamically unstable patients by attempting colonoscopy first 1
• Avoid relying solely on flexible sigmoidoscopy for bright red rectal bleeding, as studies show that colonoscopy is more cost-effective and safer, with up to 9% of patients having proximal sources of bleeding beyond sigmoidoscope reach 4, 5
• Do not place nasogastric tubes routinely in suspected upper GI bleeding as they do not reliably aid diagnosis, do not affect outcomes, and can cause complications 1