A 24-year-old man has regular upper abdominal pain for 1 year, and it worsens with hunger or at night. The patient reports black stool 2 days ago and 300ml bloody vomitus today. Which of the following test should not be considered? A: Emergent gastroscopy B: Emergent barium swallow study of gastrointestinal tract C: Ultrasound scan for upper abdominal D: Routine blood tests E: Barium swallow study of gastrointestinal tract after stool color returns to normal