Iron deficiency anaemia

Iron deficiency anaemia (IDA) occurs in 2–5% of adult men and post-menopausal women in the developed world and is a common cause of referral to a gastroenterology clinic (4–13% of referrals). While menstrual blood loss is the commonest cause of IDA in pre-menopausal women (10-15 % young woman maybe iron deficient as aresult of menstrual loss), blood loss from the gastrointestinal tract is the commonest cause in adult men and post-menopausal women. The diagnostic criteria for anaemia in IDA vary (Hb <10–11.5 g/dl for women and <12.5–13.8 g/dl for men) between studies. Serum ferritin concentration is the most powerful test for iron deficiency. A serum ferritin concentration of <12 μg/dl is diagnostic of iron deficiency.

Examination of both the upper and lower gastrointestinal tract is an important part of the investigation of patients with IDA and iron deficiency. In the absence of overt blood loss or any obvious cause, all patients should have gastroscopy with small bowel (duodenal) biopsy and colonoscopy to exclude gastrointestinal malignancy. Additional investigations that may need to be considered include capsule endoscopy.