Gastrointestinal Evaluation of Iron Deficiency Anemia

Publication Date: August 15, 2020
Last Updated: March 14, 2022

Recommendation Statements 

In patients with anemia, the AGA recommends using a cutoff of 45 ng/mL over 15 ng/mL when using ferritin to diagnose iron deficiency. (High, Strong)
Comment: In patients with inflammatory conditions or chronic kidney disease, other laboratory tests such as C-reactive protein, transferrin saturation, or soluble transferrin saturation, may be needed in conjunction with ferritin to diagnose iron deficiency anemia.

In asymptomatic postmenopausal women and men with iron deficiency anemia, the AGA recommends bidirectional endoscopy over no endoscopy. (Moderate, Strong)

In asymptomatic premenopausal women with iron deficiency anemia, the AGA suggests bidirectional endoscopy over iron replacement therapy only. (Moderate, Conditional (weak))
Comment: Patients who place a high value on avoiding the small risk of endoscopy, particularly those who are young and might have other plausible reasons for IDA, and a low value on the very small risk of missing a gastrointestinal malignancy would reasonably select an initial course of iron replacement therapy and no initial bidirectional endoscopy.

In patients with iron deficiency anemia without other identifiable etiology after bidirectional endoscopy, the AGA suggests noninvasive testing for Helicobacter pylori, followed by treatment if positive, over no testing. (Low, Conditional (weak))

In patients with iron-deficiency anemia, the AGA suggests against the use of routine gastric biopsies to diagnose atrophic gastritis. (Very Low, Conditional (weak))

In asymptomatic adult patients with iron deficiency anemia and plausible celiac disease, the AGA suggests initial serologic testing, followed by small bowel biopsy only if positive, over routine small bowel biopsies. (Very Low, Conditional (weak))
Comment: Celiac disease is a well-recognized cause of iron deficiency anemia, even in asymptomatic patients, and, therefore it must be considered in the differential diagnosis of iron deficiency anemia.

In uncomplicated asymptomatic patients with iron deficiency anemia and negative bidirectional endoscopy, the AGA suggests a trial of initial iron supplementation over the routine use of video capsule endoscopy. (Very Low, Conditional (weak))
Comment: Caution needs to be applied in patients with comorbid conditions where the identification of small bowel pathology will change medical management, such as the use of anticoagulation and/or antiplatelet therapy.

Recommendation Grading




Gastrointestinal Evaluation of Iron Deficiency Anemia

Authoring Organization

Publication Month/Year

August 15, 2020

Last Updated Month/Year

July 10, 2023

Supplemental Implementation Tools

Document Type


External Publication Status


Country of Publication


Inclusion Criteria

Female, Male, Adolescent, Adult, Child, Older adult

Health Care Settings

Ambulatory, Hospital, Laboratory services, Outpatient

Intended Users

Nurse, nurse practitioner, physician, physician assistant


Assessment and screening, Diagnosis

Diseases/Conditions (MeSH)

D007501 - Iron, D018798 - Anemia, Iron-Deficiency


environmental control, IDA

Supplemental Methodology Resources

Technical Review