Summary

Iron deficiency anaemia in men and post-menopausal women is most commonly caused by gastrointestinal blood loss or malabsorption. Examination of both the upper and lower gastrointestinal tract is therefore an important part of the investigation of patients with such anaemia. In the absence of overt blood loss or any obvious cause, all patients should have upper gastrointestinal endoscopy, including small bowel biopsy, and colonoscopy or barium enema to exclude gastrointestinal malignancy. Further gastrointestinal investigation is only warranted in transfusion dependent anaemia or where there is visible blood loss. Treatment of an underlying cause will cure the anaemia but even when no cause is detected the long term outlook is good.

1.0 Introduction

Iron deficiency anaemia (IDA) occurs in 2–5% of adult men and post-menopausal women in the developed world1 2 and is a common cause of referral to a gastroenterology clinic (4–13% of referrals).3 While menstrual blood loss is the commonest cause of IDA in pre-menopausal women, blood loss from the gastrointestinal (GI) tract is the commonest cause in adult men and post-menopausal women.4-8 Asymptomatic colonic and gastric carcinoma may present with IDA and exclusion of these conditions is of prime concern. Malabsorption (most frequently from coeliac disease), poor dietary intake, previous gastrectomy, and NSAID use are not unusual but there are many other possible causes (table 1). The management of IDA is often suboptimal with most patients being incompletely investigated if at all.9

These guidelines are primarily for gastroenterologists and GI surgeons but would be applicable to other doctors seeing patients with IDA.

The investigation of overt blood loss is not considered in these guidelines.

2.0 Definitions

2.1 ANAEMIA

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. The lower limit of the …