Iron deficiency anemia in patients without gastrointestinal symptoms--a prospective study

Chronic gastrointestinal (GI) bleeding is the leading cause of iron deficiency anaemia (IDA) in men older than 50 years and post-menopausal women. There is a scarcity of data regarding IDA patients without GI symptoms or signs. We conducted a prospective study to determine the prevalence and the locations of the GI tract lesions in patients with asymptomatic IDA.

Forty-eight patients with asymptomatic IDA (25 men older than 50 years and 23 post-menopausal women) underwent colonoscopy, gastroscopy and abdominal computed tomography (CT) with contrast agent.

An anaemia-causing lesion was found in 14 (29%) and 16 (33%) patients in the upper and the lower GI tract, respectively. The prevalence of dual lesions (in both the upper and lower GI tract) was low (6%). In 14 (29%) patients, a malignancy, predominantly right-sided colon carcinoma, was responsible for the IDA. Only one patient had a lesion in the small bowel. In 14 (29%) patients, the work-up was negative.

Our prospective study demonstrates a high rate of malignancy, predominantly right-sided colon carcinoma, in men older than 50 years and post-menopausal women with asymptomatic IDA. This finding obligates a complete and rigorous GI tract examination in this group of patients, especially of the right colon.