Gastroenterology and Hepatologycommon
A 68-year-old man presents with three months of increasing tiredness and breathlessness climbing stairs. He eats a mixed diet, takes no regular medications, and reports no change in bowel habit and no visible bleeding. Examination shows pale conjunctivae; abdominal and rectal examinations are normal. Investigations show haemoglobin 92 g/L (130–180), mean corpuscular volume 71 fL (80–100) and serum ferritin 8 microg/L (30–300). Which one of the following is the most appropriate next step in investigation?