What is the appropriate workup and treatment for a 44-year-old male with iron deficiency anemia?

Workup and Treatment of Iron Deficiency Anemia in a 44-Year-Old Male

A 44-year-old male with iron deficiency anemia requires both upper endoscopy with small bowel biopsy and colonoscopy (or barium enema) to identify the source of blood loss, as men at this age have significant risk of gastrointestinal malignancy, followed by oral iron supplementation with ferrous sulfate 200 mg three times daily. 1

Diagnostic Workup

Initial Laboratory Confirmation

• Confirm iron deficiency using serum ferritin <45 mg/dL as the most efficient diagnostic marker 1
• Check hemoglobin, hematocrit, and red blood cell indices to assess severity 2
• Measure transferrin saturation if ferritin is borderline or if inflammatory conditions are suspected 1

Mandatory Gastrointestinal Investigation

Because this patient is over 45 years old and male, he requires complete bidirectional endoscopy regardless of symptoms. 1 The British Society of Gastroenterology guidelines specifically state that patients over 45 years should be investigated according to full protocols due to increasing incidence of important pathology with age 1

• Upper endoscopy with small bowel biopsy to evaluate for:

  • Gastric or duodenal ulcers
  • Gastric cancer
  • Celiac disease (via duodenal biopsy) 1, 3
  • Helicobacter pylori infection 1

• Colonoscopy or barium enema to evaluate for:

  • Colon cancer (7 times more common than upper GI cancer in this population) 3
  • Colonic polyps
  • Inflammatory bowel disease 3

Additional Testing

• Test for celiac disease with anti-endomysial antibody and IgA levels (IgA deficiency makes the test unreliable) 1
• Stool guaiac testing for occult blood 4
• Assess dietary iron intake 1

When to Consider Small Bowel Investigation

Small bowel capsule endoscopy or CT/MRI enterography should be performed only if bidirectional endoscopy is negative AND there are red flags such as involuntary weight loss, abdominal pain, or elevated CRP 3

Iron Replacement Therapy

First-Line Oral Iron

Initiate ferrous sulfate 200 mg (containing 65 mg elemental iron) three times daily 1, 5

• This is the most cost-effective and simplest approach 1
• Alternative formulations include ferrous gluconate or ferrous fumarate if ferrous sulfate is not tolerated 1
• Consider adding ascorbic acid (vitamin C) to enhance absorption if response is poor 1
• Liquid preparations may be better tolerated than tablets in some patients 1

Alternative Dosing Strategy

If gastrointestinal side effects occur, consider alternate-day dosing (ferrous sulfate 325 mg every other day) to improve tolerability 4

When to Use Parenteral Iron

Reserve intravenous iron for specific situations only 1:

• Intolerance to at least two different oral iron preparations
• Documented non-compliance with oral therapy
• Malabsorption syndromes (e.g., celiac disease, inflammatory bowel disease with active inflammation) 1

Important caveat: Parenteral iron is painful when given intramuscularly, expensive, carries risk of anaphylactic reactions, and provides no faster hemoglobin rise than oral preparations 1

Monitoring Response to Treatment

Expected Response Timeline

• Recheck hemoglobin after 3-4 weeks 1, 4
• Expected rise: 2 g/dL over 3-4 weeks 1
• Continue iron for 3 months after hemoglobin normalization to fully replenish body stores 4

Failure to Respond

If hemoglobin does not rise appropriately after 3-4 weeks, consider 1:

• Poor compliance (most common cause)
• Misdiagnosis
• Continued blood loss
• Malabsorption

Long-Term Monitoring

• Monitor hemoglobin and erythrocyte indices every 3 months for one year, then annually 4

Quality Targets

The British Society of Gastroenterology recommends the following audit standards 1:

• 90% of male patients with iron deficiency anemia should have both upper endoscopy with small bowel biopsy AND colonoscopy (unless a firm cause is found with the first investigation)
• Resolution of anemia should be achieved by 6 months in 80% of patients
• 90% of non-responders should be considered for further investigation

Critical Pitfalls to Avoid

• Do not skip gastrointestinal investigation in men, even if dietary intake seems inadequate—gastrointestinal blood loss from malignancy must be excluded 1, 3, 6
• Do not use parenteral iron as first-line therapy unless there is documented intolerance or malabsorption 1
• Do not stop investigating if the first endoscopy is negative—both upper and lower GI tract must be evaluated 1
• Do not assume treatment failure is due to poor compliance alone—reassess for continued blood loss or malabsorption 1