This document presents the official recommendations of the American Gastroenterological Association (AGA) on the gastrointestinal evaluation of iron deficiency anemia (IDA). The guideline was developed by the AGA Institute’s Clinical Guidelines Committee and approved by the AGA Governing Board. It is accompanied by a technical review that provides a detailed synthesis of the evidence from which these recommendations were formulated.1 For a better understanding of this guideline, we recommend reading the accompanying technical review.