UKMLA PLAB AMC USMLE Prometric MCQ

Question Number 0788

Question:
A 6 day old infant male vomits a large amount of bright red blood at home and is taken to a rural emergency department. He is currently breast feeding. He is passing stools and urinating well. A guaiac of the red material on the blanket that the baby vomited was positive. The most appropriate investigation at this stage would be:

a) Apt test
b) frontal radiograph that includes the neck, chest and entire abdomen
c) 24 hr esophageal pH probe test
d) CT abdomen
e) ultrasound of the abdomen