Inflammatory Bowel Disease USMLE Step 1 Practice Question
A 29-year-old man with newly diagnosed Crohn disease limited to the terminal ileum presents with abdominal pain, bloody diarrhea, and fever (38.2°C). Vital signs: BP 118/76, HR 92, RR 18, SpO2 98% on room air. He denies melena. Laboratory studies reveal hemoglobin 9.8 g/dL, MCV 72 fL, ferritin 15 ng/mL, iron saturation 16%, and normal B12 level. CT enterography confirms segmental inflammation. Which of the following best explains his anemia?
Answer choices
- AFolate deficiency from sulfasalazine use
- BAutoimmune hemolytic anemia secondary to IBD
- CVitamin B12 deficiency from terminal ileal disease
- DChronic disease anemia from inflammation alone
- EIron deficiency anemia from chronic GI blood lossCorrect answer
- FAnemia of chronic kidney disease from reduced erythropoietin production
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