Final answer:
The best initial test for suspicion of Zollinger-Ellison Syndrome is the secretin-pancreozymin test, which evaluates pancreatic exocrine function. Stimulation tests can also be used to study the secretory and motor activity of the stomach. Further imaging, endoscopy, and lab tests may be necessary for a definitive diagnosis.
Step-by-step explanation:
The best initial test for suspicion of Zollinger-Ellison Syndrome is the secretin-pancreozymin test. This test evaluates the pancreatic exocrine function by analyzing duodenal contents after an intravenous injection of secretin and pancreozymin. The test measures various factors such as volume, bicarbonate output, and enzyme concentrations.
Another type of test that can be used is the stimulation tests, which study the secretory and motor activity of the stomach by stimulating it with substances like pentagastrin, alcohol, caffeine, histamine, and insulin. Gastric contents are aspirated and analyzed to determine the levels of acids.
It's important to note that these initial tests can help raise suspicion of Zollinger-Ellison Syndrome, but a definitive diagnosis may require further imaging, endoscopy, and lab tests.