Does this elderly patient have iron deficiency anaemia, and what is the underlying cause?

Important implications for the recognition of iron deficiency anaemia include diagnosis and correction of underlying causes, most of which are identifiable, in the older patient, by means of conventional upper gastrointestinal endoscopy, and by colonoscopy. The aetiological search may, however, have to be widened to include enteroscopic examination of the jejunum and ileum and, in some instances, investigation of potential non-gastrointestinal foci of chronic blood loss. A substantial minority may defy even the most thorough search for the underlying cause.