Should a patient with anemia (low red blood cell count) and a history of stomach surgery be evaluated by a gastroenterologist for potential stomach bleeding?

Should a Patient with Anemia and Prior Stomach Surgery Undergo Gastroenterology Evaluation?

Yes, a patient with anemia and a history of stomach surgery should absolutely be evaluated by gastroenterology, because even though prior gastric surgery commonly causes iron deficiency anemia, it is unsafe to automatically attribute the anemia to the surgery without excluding other potentially serious causes, including malignancy in the gastric remnant. 1

Why Gastroenterology Evaluation is Essential

Prior Surgery Does Not Exclude Other Causes

• A history of GI or bariatric surgery should not preclude a comprehensive search for other causes of iron deficiency anemia, according to the British Society of Gastroenterology 2021 guidelines with strong consensus (85%). 1

• While stomach/small bowel resection or bypass surgery does predispose to iron deficiency anemia (found in approximately 25% of patients 2 years post-Roux-en-Y gastric bypass), the yield of other causative bleeding lesions is lower but still significant in patients with prior GI surgery. 1

• Partial gastrectomy may predispose to the later development of cancer in the gastric remnant, making evaluation particularly critical in this population. 1

What the Gastroenterologist Should Look For

Upper and lower GI investigations should be performed unless there is documented significant non-GI blood loss: 1

• Upper endoscopy (esophagogastroduodenoscopy) reveals a bleeding source in 30-50% of patients with iron deficiency anemia and should include: 1

  • Evaluation for gastric remnant malignancy (if prior partial gastrectomy) 1
  • Assessment for peptic ulcers, erosions, or Cameron's lesions 2
  • Small bowel biopsies to screen for celiac disease (found in 2-3% of iron deficiency anemia cases) 1, 3

• Lower GI investigation (colonoscopy preferred over barium enema) should be performed even if upper endoscopy reveals findings, because: 1

  • Dual pathology (lesions in both upper and lower GI tracts) occurs in 10-15% of patients 1
  • Colorectal cancer must be excluded, particularly in those at risk 1

Critical Diagnostic Pitfall to Avoid

Do not assume the anemia is simply due to malabsorption from prior surgery without excluding bleeding lesions or malignancy. 1 This is especially important because:

• The prevalence of iron deficiency anemia increases over the first 10 postoperative years without supplementation 1
• Patients with prior gastric surgery can develop new pathology independent of their surgical history 1
• Gastrointestinal malignancy presenting with iron deficiency anemia has significant mortality implications if diagnosis is delayed 1

When to Consider Advanced Investigation

If initial upper and lower endoscopy are negative and anemia persists or is transfusion-dependent: 4

• Capsule endoscopy is recommended as the next step for obscure bleeding (angiectasias account for up to 80% of obscure bleeding) 4, 2
• CT enterography may be appropriate if contraindications to capsule endoscopy exist 4
• Double-balloon enteroscopy should be considered when therapeutic intervention may be needed 4

Treatment Considerations

Once evaluation is complete: 1

• Long-term oral iron replacement therapy is often effective in post-surgical patients, though malabsorption may necessitate intravenous therapy 1
• Treatment should not begin until diagnostic evaluation excludes other causes 1
• If Helicobacter pylori is present in patients with recurrent iron deficiency anemia and normal endoscopy, it should be eradicated 1