Q. A 52-year-old woman presents to the outpatient clinic with a four-month history of early satiety, postprandial fullness, and nausea. She occasionally experiences abdominal bloating and vomiting of undigested food a few hours after meals. She reports unintentional weight loss of 15 pounds during this period. Her past medical history is significant for poorly controlled type 2 diabetes mellitus, and she was previously diagnosed with diabetic neuropathy. Physical examination reveals a soft, non-distended abdomen with no hepatosplenomegaly or palpable masses. Mild epigastric tenderness is noted. Laboratory investigations show a fasting blood glucose level of 160 mg/dL and an HbA1c of 9.2%. Her serum electrolytes, liver function, and thyroid function tests are within normal limits. Abdominal ultrasound is unremarkable. An upper endoscopy shows a normal esophagus, stomach, and duodenum with food remnants present despite a 12-hour fast. What is the most appropriate next step in management for this patient?