From the Guidelines
A 71-year-old male with low ferritin but normal CBC who had a normal colonoscopy 5 years ago and is currently asymptomatic should undergo bidirectional endoscopy as recommended by the AGA guidelines 1. This approach is based on the American Gastroenterological Association (AGA) clinical practice guidelines on the gastrointestinal evaluation of iron deficiency anemia, which suggests bidirectional endoscopy in asymptomatic postmenopausal women and men with iron deficiency anemia 1. Key considerations in this patient's evaluation include:
- The patient's age and sex, which place him in a category where bidirectional endoscopy is recommended by the AGA guidelines 1
- The presence of low ferritin levels, which indicates iron deficiency and warrants further investigation to determine the underlying cause
- The normal CBC, which suggests that the iron deficiency is not currently severe enough to cause anemia, but still requires evaluation to prevent potential complications
- The patient's medical history, including the normal colonoscopy 5 years ago, which may not entirely rule out the possibility of new colonic lesions or other gastrointestinal sources of bleeding Additional steps in the evaluation may include:
- Serum iron panel (including iron, TIBC, and transferrin saturation) to better characterize the iron deficiency
- Medication review (particularly for NSAIDs, anticoagulants) to assess potential contributors to iron deficiency
- Dietary assessment to evaluate for poor dietary intake of iron
- Consideration of non-GI causes of iron deficiency, such as frequent blood donation or urologic sources of bleeding
- Noninvasive testing for Helicobacter pylori, followed by treatment if positive, as suggested by the AGA guidelines 1
From the Research
GI Workup for 71-Year-Old Male with Low Ferritin but Normal CBC
- The patient has low ferritin levels but a normal complete blood count (CBC) and no symptoms, with a normal colonoscopy 5 years ago 2, 3.
- Studies suggest that gastrointestinal pathology is a common cause of iron deficiency anemia (IDA), and carcinomas are more likely to cause IDA than benign adenomas 4.
- The prevalence of advanced colonic neoplasia in subjects with ferritin 51-100 ng/mL was similar to those with ferritin ≤50 ng/mL, and patients with ferritin ≤50 ng/mL and 51-100 ng/mL were almost 5 times more likely to harbor advanced colonic neoplasia than the other groups 5.
- A ferritin cutoff of 100 ng/mL can be used to determine the need for colonoscopy in men with anemia, and the diagnostic yield of endoscopy in patients with anemia, no GI symptoms or signs, and low normal ferritin is significant 2, 5.
- The American Journal of Hematology study found that upper GI findings were present in 30% of cases, and lower GI findings were present in 6.7% of cases, supporting GI endoscopy in anemic patients with ferritin between 40 and 100 ng/mL, even in the absence of GI symptoms or documented bleeding 2.
- Considering the patient's age and low ferritin levels, a GI workup, including colonoscopy, may be necessary to rule out underlying gastrointestinal pathology, despite the absence of symptoms 3, 4, 5.