Management of Iron Deficiency with GI Bleeding and Abnormal Labs
This patient requires urgent bidirectional endoscopy (both upper endoscopy and colonoscopy) regardless of the positive fecal occult blood test, along with coeliac disease screening and immediate iron supplementation. 1
Immediate Diagnostic Workup
Essential Investigations
Perform bidirectional endoscopy (gastroscopy AND colonoscopy) as the first-line investigation, even though visible blood is present, because dual pathology (lesions in both upper and lower GI tracts) occurs in 10-15% of patients and increases with age 1, 2
Screen for coeliac disease using tissue transglutaminase antibody (with IgA level) before or during endoscopy, as 2-3% of iron deficiency anemia patients have coeliac disease as a non-bleeding cause 1, 2
Obtain small bowel biopsies during upper endoscopy even if the mucosa appears normal, as coeliac disease may not be visually apparent 1, 2
Do NOT rely on the fecal occult blood test for diagnostic purposes—it is of no benefit in the investigation of iron deficiency anemia and should not guide your workup 1
Critical Pitfall to Avoid
Do not stop investigating after finding minor upper GI lesions (such as oesophagitis, erosions, or peptic ulcer)—proceed with colonoscopy regardless, as these should not be accepted as the sole cause of iron deficiency at this stage 1
Interpretation of Abnormal Labs
The low EPO (erythropoietin = 3) with normal-high hemoglobin is unusual and warrants consideration of:
Relative erythropoietin deficiency despite iron deficiency, which may indicate chronic disease component or renal issues 1
The elevated immune markers (C4 = 100, though C3 is low at 19) and rheumatoid factors suggest possible underlying inflammatory or autoimmune process that could contribute to both GI pathology and anemia 3
Document NSAID/aspirin use and stop if possible, as these are common causes of iron deficiency anemia, though their use should not deter full investigation 1
Immediate Management
Iron Replacement
Start iron supplementation immediately (100-200 mg elemental iron daily) to correct anemia and replenish body stores—do not defer while awaiting investigations unless colonoscopy is imminent 1, 2
Consider parenteral iron if oral preparations are not tolerated or if there is evidence of malabsorption 1
Reserve blood transfusions only for patients with or at risk of cardiovascular instability due to the degree of anemia 1
If Initial Endoscopy is Negative
Further Small Bowel Investigation
Small bowel visualization is indicated if:
- Hemoglobin cannot be restored or maintained with iron therapy 1
- There are symptoms suggestive of small bowel disease 1
- Anemia is transfusion-dependent or recurrent 2, 4
Capsule endoscopy is the preferred test for examining the small bowel, with diagnostic yield of 61-74%, followed by CT or MRI enterography if capsule endoscopy is not suitable 2, 5
Additional Considerations
Test for and eradicate Helicobacter pylori if present in patients with recurrent iron deficiency anemia and normal initial endoscopies 1
Perform urinalysis to exclude urinary tract bleeding as a rare cause 2
Repeat endoscopy may find missed lesions in 35% of patients with initially negative findings and recurrent bleeding 5
Key Clinical Points
The combination of visible GI bleeding with positive fecal occult blood test, low ferritin, and low transferrin saturation confirms iron deficiency anemia requiring full investigation regardless of the patient's age or gender 1. The abnormal immune markers and low EPO suggest this may be more complex than simple GI blood loss alone, making thorough evaluation even more critical. Dietary deficiency should never be assumed as the sole cause, and full GI investigation is required even with a positive dietary history 1.