Is there a relationship between iron deficiency anemia and gastrointestinal bleeding?
Iron deficiency anemia is usually diagnosed by a hemoglobin value of less than 12 g/dl and a serum ferritin level of less than 45 ug/l. In the U.S., 5-11% of women have iron deficiency anemia, often on a basis of menstrual bleeding problems. However, chronic occult gastrointestinal bleeding is also a frequent cause of iron deficiency. Anytime a woman is diagnosed with anemia and it turns out to be of the iron deficient form, an investigation should be made to make sure the blood loss is not from somewhere other than menses. At a minimum, a test for fecal occult blood should be performed. As much as 12% of iron deficiency anemia in premenopausal women may be due to serious gastrointestinal anomalies. What happens if they can’t find the cause for a positive fecal occult blood test? When the work up to evaluate occult fecal blood is completed (see colon cancer screening article below), about 5% of patients with gastrointestinal bleeding will not have a source for their bleeding found. In
