A 35-year-old man is referred for the evaluation of GERD symptoms. His primary symptom is regurgitation, although he occasionally experiences heartburn as well. He was started on once daily PPI for 2 months and only experienced mild relief in symptoms. His dosage was increased to twice daily for an additional month without much improvement. He denies any dysphagia, weight loss, early satiety, or melena. He is otherwise healthy and takes no other medications.
Which of the following would be recommended?
A. Ambulatory 24-hour pH/impedance study
B. Upper endoscopy
C. Barium esophagram
D. Switch PPI to H2 receptor antagonist