Coded Gastrointestinal Diagnoses in Women Aged 18-44 Years with Iron Deficiency Anemia Without Selected Coded Alarm Features Who Underwent Same-Day Bidirectional Endoscopy: A Multicenter U.S. Electronic Health Record Study.

Scope: the guideline covers adults with IDA without dominant GI symptoms (its definition of 'asymptomatic'); in patients WITH GI symptoms, endoscopy is directed first at the symptomatic segment, and the uninvestigated side is examined if that is negative. (1) In patients with anemia, use a ferritin cutoff of 45 ng/mL rather than 15 ng/mL to diagnose iron deficiency (strong recommendation, high-certainty evidence); in inflammatory conditions or CKD, adjunct tests (CRP, transferrin saturation) may be needed. (2) In asymptomatic postmenopausal women and men with IDA, perform bidirectional endoscopy (EGD plus colonoscopy) rather than no endoscopy (strong recommendation, moderate certainty); when both procedures are needed they should be performed on the same day, a practical consideration stated in the guideline, not part of the graded recommendation. (3) In asymptomatic premenopausal women with IDA, the AGA suggests bidirectional endoscopy over iron replacement therapy alone (conditional recommendation, moderate certainty); shared decision-making applies, and a patient who places higher value on avoiding endoscopy may reasonably choose an initial trial of iron. (4) In IDA with no etiology identified after bidirectional endoscopy, the AGA suggests noninvasive H. pylori testing (urea breath test, stool antigen, or serology per the technical review), with treatment if positive, over no testing (conditional, low certainty), a post-endoscopy step. (5) The AGA suggests against routine gastric biopsies to diagnose atrophic gastritis (conditional, very low certainty). (6) In asymptomatic adults with IDA and plausible celiac disease, the AGA suggests initial serologic testing, with small-bowel biopsy only if serology is positive, over routine small-bowel biopsies (conditional, very low certainty). (7) In uncomplicated asymptomatic patients with IDA and negative bidirectional endoscopy, the AGA suggests an initial trial of iron supplementation over routine video capsule endoscopy (conditional, very low certainty); VCE is second-line, for persistent or recurrent IDA despite iron therapy. The guideline does, however, advise caution in patients with comorbid conditions in whom identifying small-bowel pathology would change management: in selected such patients, for example, those on ongoing anticoagulation or antiplatelet therapy, those who are transfusion-dependent, or those with refractory IDA, VCE may reasonably be considered earlier, even as a first-line investigative approach, because identifying a small-bowel bleeding lesion may change management. This is an individualized judgment for particular patients, not a categorical exception that exempts these groups from the iron-first approach.