A 67-year-old man comes to the physician for a 4-month history of abdominal pain 1-2 hours after eating meals. He has a 20-year history of type II diabetes mellitus and hypertension managed with multiple medications. He had coronary artery bypass grafting 4 years ago. Which of the following is the most appropriate next step in diagnosis?
24-hour esophageal pH monitoring
Angiography
Ankle-brachial indices
Colonoscopy
Stool antigen
Urea breath test
