skip to main content

Iron deficiency anemia from occult gastrointestinal blood loss — USMLE Step 3 MCQ

Instant feedback + full explanation. One question, done properly.

ModerateAmbulatory Medicine / Primary CareIron deficiency anemia from occult gastrointestinal blood lossUSMLE Step 3

A 62-year-old woman reports 3 months of fatigue and reduced exercise tolerance. Hemoglobin is 9.8 g/dL, mean corpuscular volume is 72 fL, ferritin is 8 ng/mL, and fecal occult blood testing is positive. She has no abdominal pain, weight loss, or change in bowel habits. Her last colonoscopy was 11 years ago. Which of the following is the most appropriate next step in management?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — Perform colonoscopy and upper endoscopy

Iron deficiency anemia in an adult without an obvious source requires evaluation for gastrointestinal blood loss and malignancy. Bidirectional endoscopy is the appropriate diagnostic approach rather than empiric iron alone.

Reference: American Gastroenterological Association guideline on iron deficiency anemia