Key Points
- Anemia is a common diagnosis in both men and women, and iron deficiency is the most common cause of anemia worldwide.
- The aim of this guideline is to outline an evidence-based approach to the initial diagnosis and evaluation of this commonly encountered clinical condition.
Treatment
GI Evaluation of Iron Deficiency Anemia Clinical Decision Support Tool

GI Evaluation of Iron Deficiency Anemia Clinical Decision Support Tool (cont’d)

Recommendationsª
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 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.
GRADE Strength of Recommendations and Implications
Source Citation
Ko, C., Siddique, S., Patel, A., Harris, A., Sultan, S., Altayar, O., & Falck-Ytter, Y. (2020). AGA Clinical Practice Guidelines on the Gastrointestinal Evaluation of Iron Deficiency Anemia. Gastroenterology, 159(3), 1085-1094. doi: 10.1053/j.gastro.2020.06.046
Disclaimer
This resource is for informational purposes only, intended as a quick-reference tool based on the cited source guideline(s), and should not be used as a substitute for the independent professional judgment of healthcare providers. Practice guidelines are unable to account for every individual variation among patients or take the place of clinician judgment, and the ultimate decision concerning the propriety of any course of conduct must be made by healthcare providers after consideration of each individual patient situation. Guideline Central does not endorse any specific guideline(s) or guideline recommendations and has not independently verified the accuracy hereof. Any use of this resource or any other Guideline Central resources is strictly voluntary.