Inflammatory Bowel Disease USMLE Step 1 Practice Question
A 29-year-old woman with a 4-year history of Crohn disease presents to clinic for follow-up evaluation. She reports persistent loose stools (4-5 per day) and intermittent crampy abdominal pain despite adherence to mesalamine. Vital signs are stable. Laboratory findings: hemoglobin 8.2 g/dL, hematocrit 26%, MCV 68 fL, ferritin 8 ng/mL, serum iron 35 μg/dL (normal 60-170), TIBC 520 μg/dL (normal 250-425). Reticulocyte count is 1.8% (normal 0.5-2.5%). Fecal calprotectin is elevated at 850 μg/g. Recent colonoscopy showed patchy inflammation with skip lesions and shallow ulcerations but no active gross bleeding. She denies hematochezia. Which of the following best explains her anemia?
Answer choices
- AVitamin B12 deficiency from impaired terminal ileal absorption
- BIron deficiency from chronic occult blood loss and mucosal diseaseCorrect answer
- CFolate deficiency from sulfasalazine-induced malabsorption
- DAnemia of chronic inflammation without significant iron depletion
- EHemolytic anemia secondary to autoimmune phenomenon associated with IBD
- FMacrocytic anemia from impaired duodenal nutrient uptake
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