Final answer:
To diagnose delayed gastric emptying, a gastric function test is the initial step, followed by stimulation tests or endoscopic ultrasound for conditions like diabetic gastroparesis. These procedures help to analyze gastric secretory and motor function in detail.
Step-by-step explanation:
The first test to order in patients with delayed gastric emptying is a gastric function test, specifically one that measures gastric secretory activity. If diabetic gastroparesis or another motility disorder is suspected, the patient will require stimulation tests or an endoscopic ultrasound to confirm the diagnosis.
Gastric function tests are essential in assessing conditions such as duodenal ulcers, gastric cancer, and pernicious anemia. In the context of diabetic patients, it is important to determine if there are underlying motility disorders, which may require additional diagnostic procedures such as stimulation tests or endoscopic ultrasounds. These tests help to evaluate the motor and secretory activities of the stomach and can provide detailed information about the patient's condition.
For example, stimulation tests involve the use of agents like pentagastrin to provoke gastric secretion and measure various aspects such as acid production.