What is the best course of action for a patient presenting with anemia of chronic disease and evidence of gastrointestinal bleeding?

Management of Anemia with High Ferritin, Low Iron, Low TIBC, and Positive Fecal Occult Blood

This patient requires urgent bidirectional endoscopy (both upper endoscopy and colonoscopy) to identify the source of gastrointestinal bleeding, as the positive fecal occult blood test indicates active GI blood loss that must be investigated regardless of the anemia pattern. 1

Understanding the Laboratory Pattern

Your patient's laboratory findings suggest anemia of chronic disease with concurrent gastrointestinal bleeding:

• High ferritin with low iron and low TIBC is the classic pattern of anemia of chronic disease (also called anemia of inflammation), where iron is sequestered in storage but unavailable for erythropoiesis 1
• However, the positive fecal occult blood test indicates active GI bleeding that requires investigation regardless of the ferritin level 1
• In patients with inflammatory conditions, iron deficiency can coexist with elevated ferritin (typically ferritin 45-100 mg/dL), making transferrin saturation <30% a helpful confirmatory test 1

Immediate Diagnostic Approach

First-Line Investigations (Perform Urgently)

Proceed with bidirectional endoscopy as the initial diagnostic step:

• Upper endoscopy (EGD) should be performed first in most cases, as it reveals bleeding sources in 30-50% of patients with occult GI bleeding 1
• During upper endoscopy, obtain small bowel biopsies to screen for celiac disease, which accounts for 2-3% of iron deficiency anemia cases and can contribute to malabsorption 1
• Colonoscopy must follow unless upper endoscopy reveals carcinoma or celiac disease, because dual pathology (lesions in both upper and lower GI tract) occurs in 10-15% of patients 1
• In elderly patients, colonoscopy may be more productive and can be prioritized 1

Additional Initial Testing

• Urinalysis or urine microscopy to exclude renal causes of blood loss 1
• Celiac serology (tissue transglutaminase antibodies) if small bowel biopsy not obtained 1
• Stop NSAIDs and aspirin if being used, though their use should not delay investigation 1

Common Pitfalls to Avoid

Do not accept superficial lesions as the sole cause of bleeding:

• Esophagitis, gastric erosions, aphthous ulceration, and peptic ulcers should not be immediately accepted as the definitive cause without completing lower GI evaluation, given the 10-15% rate of dual pathology 1

Do not defer iron replacement while awaiting investigations:

• Begin oral iron supplementation immediately (ferrous sulfate, fumarate, or gluconate one tablet daily) unless colonoscopy is imminent 1
• A hemoglobin rise ≥10 g/L within 2 weeks confirms iron deficiency even if iron studies are equivocal 1

If Initial Endoscopy is Negative

For patients with negative bidirectional endoscopy but ongoing anemia or inadequate response to iron therapy:

• Capsule endoscopy is the preferred test for examining the small bowel, as it is highly sensitive for mucosal lesions 1
• Angiodysplasia accounts for up to 80% of obscure bleeding sources 1
• In patients younger than 50 years, be aggressive in investigation as small bowel tumors are the most common cause of obscure bleeding in this age group 1
• CT or MR enterography can be considered if capsule endoscopy is not suitable, particularly for inflammatory or neoplastic disease 1

Treatment Strategy

Iron Replacement

• Start with oral iron (one tablet daily of ferrous sulfate, fumarate, or gluconate) 1
• If not tolerated, reduce to one tablet every other day or consider alternative preparations 1
• Consider intravenous iron if:
  • Patient has ongoing bleeding and does not respond to oral iron 1
  • Active inflammation is present with compromised absorption 1
  • Oral iron is not tolerated 1

Addressing the Underlying Cause

• Treat any identified GI lesions appropriately (endoscopic therapy for angiodysplasia, surgical resection for malignancy, etc.) 1
• Manage underlying inflammatory conditions effectively to enhance iron absorption and reduce iron depletion 1
• If portal hypertensive gastropathy is identified, consider nonselective β-blockers to reduce bleeding 1

Follow-Up Considerations

• After negative capsule endoscopy of acceptable quality, further GI investigation is only needed if there is ongoing iron deficiency anemia after iron replacement therapy 1
• Long-term iron replacement therapy may be appropriate when the cause of recurrent anemia is unknown or irreversible 1
• Hemoglobin levels normalize with iron replacement in most cases, but anemia recurs in a minority on long-term follow-up, requiring continued monitoring 1