Practical gastrointestinal investigation of iron deficiency anaemia

About 10% of oesophagogastroduodenoscopies (OGDs) and colonoscopies are done for investigation of iron deficiency anemia (IDA) . Much of the existing guidance on investigation of IDA predates CRC screening, which has driven significant improvements in colonoscopy quality and completion rates, as well as a reduction in Helicobacter pylori prevalence and increase in PPI usage, and therefore probably needs re-consideration. New investigations, e.g. CT colonography, enteroscopy and capsule endoscopy have also been introduced. Areas covered: This review updates the approach to practical investigation of IDA. Medline was searched using the terms iron deficiency AND anemia AND/OR gastroscopy, colonoscopy, capsule and enteroscopy, together with review of recent relevant published abstracts on the topic. Expert commentary: Gastrointestinal pathology is now a more common cause of IDA than upper GI causes, reflecting better colonoscopy accuracy and completion rates as well as changing disease patterns, and carcinomas are more likely cause IDA than benign adenomas. Increasing use of antiplatelet and anticoagulants is driving greater presentation of IDA. Capsule endoscopy, enteroscopy and CT colonography are increasingly used. Fecal occult blood testing may be a useful simple screening method in the frail, as a negative test can avoid the need for invasive tests.