What is the best course of action for a patient with a history of a single episode of hematochezia (passage of red blood per rectum) 16 days prior, now presenting with severe anemia (hemoglobin level of 2 g/dL) and no other episodes of melena (black tarry stools) or hematochezia?

Immediate Management of Severe Anemia with Prior Hematochezia

This patient requires immediate blood transfusion to a hemoglobin target of at least 7 g/dL, urgent bidirectional endoscopy (both upper and lower) within 24 hours, and full colonoscopy regardless of any findings on anoscopy, as a hemoglobin of 2 g/dL represents life-threatening anemia that cannot be attributed to hemorrhoids alone. 1, 2

Critical Initial Resuscitation

• Transfuse packed red blood cells immediately to maintain hemoglobin >7 g/dL (target 7-9 g/dL), as this represents severe anemia requiring urgent correction 1
• Establish large-bore IV access and begin crystalloid resuscitation targeting mean arterial pressure >65 mmHg while avoiding fluid overload 1, 3, 4
• Obtain complete blood count, coagulation parameters (PT/INR, aPTT, platelet count, fibrinogen), blood urea nitrogen, creatinine, and type and cross-match 3, 4
• Calculate shock index (heart rate/systolic BP); a value >1 indicates hemodynamic instability requiring more aggressive resuscitation 4

Mandatory Diagnostic Workup

Why Both Upper and Lower Endoscopy Are Required

Full colonoscopy is absolutely mandatory despite the history of red stool, as:

• The risk of colorectal cancer in patients with rectal bleeding ranges from 2.4-11%, making complete colonic evaluation essential 1, 2
• Hemorrhoids cause anemia in only 0.5 per 100,000 population per year—this degree of anemia (Hgb 2) essentially rules out hemorrhoids as the sole cause 2, 5
• Operating on or attributing severe anemia to hemorrhoids without excluding proximal colonic pathology is a critical error that could delay cancer diagnosis 2

Upper endoscopy must also be performed because:

• 15% of patients presenting with serious hematochezia (defined as hemoglobin drop ≥1.5 g/dL or transfusion requirement) have an upper GI source identified at upper endoscopy 1
• Even in patients with confirmed diverticulosis and hematochezia, 8% have an upper GI bleeding source 1
• A potential bleeding source in the upper GI tract would be missed in 25% of patients if only colonoscopy were performed 6

Timing and Sequence of Endoscopy

• Perform urgent bidirectional endoscopy within 24 hours after hemodynamic stabilization 1, 3
• Consider upper endoscopy first to exclude an upper GI source, particularly given the severity of anemia 3, 6
• Ensure adequate bowel preparation to improve mucosal visualization and diagnostic yield 3

Special Diagnostic Considerations

Evaluate for Coagulopathy

Given the severity of anemia with only one reported bleeding episode, assess for:

• Anticoagulant use (warfarin, DOACs, heparin) that can cause both GI bleeding and impaired hemostasis 4
• Thrombocytopenia from medications, hematologic disorders, or liver disease 4
• Liver disease with portal hypertension causing coagulopathy and potential anorectal varices 4
• Disseminated intravascular coagulation (DIC) in critically ill patients 4
• Inherited bleeding disorders (hemophilia, von Willebrand disease) 4

If Anorectal Varices Are Suspected

• Look for history of portal hypertension or liver disease 1, 4
• Anorectal varices appear as discrete, compressible, serpiginous submucosal veins crossing the dentate line extending into the rectum (unlike hemorrhoids confined to the anal canal) 1, 4
• If varices are confirmed with severe bleeding, initiate prophylactic antibiotics, consider vasoactive drugs (terlipressin or octreotide), and involve hepatology early 1

Critical Pitfalls to Avoid

• Never attribute hemoglobin of 2 g/dL to hemorrhoids without complete evaluation—hemorrhoids typically cause minor, intermittent bleeding that does not result in significant anemia 2
• Do not perform hemorrhoidectomy or local hemorrhoid treatment without first excluding proximal colonic and upper GI pathology 2
• Avoid over-transfusion in patients with potential portal hypertension, as fluid overload can exacerbate portal pressure and increase rebleeding risk 1
• Do not delay endoscopy for excessive bowel preparation in unstable patients—proceed with available preparation 3

Post-Procedure Monitoring

• If hemorrhoids are ultimately confirmed as the source after negative bidirectional endoscopy, initiate iron replacement therapy and plan definitive hemorrhoid treatment 2
• Hemoglobin should recover rapidly after definitive treatment (mean 12.3 g/dL at 2 months, 14.1 g/dL at 6 months) 5
• Failure to recover hemoglobin after treatment mandates repeated evaluation for other bleeding sources 2, 5