Secretin: What It Does, How Tests Work, and Safety Tips
Secretin is a hormone your small intestine makes when acidic food leaves the stomach. It tells the pancreas to release bicarbonate to neutralize stomach acid and helps bile flow. Doctors use synthetic secretin mainly as a test to check pancreatic function and to help find gastrin-secreting tumors called Zollinger–Ellison syndrome. The test and the hormone matter if you have unexplained stomach pain, chronic pancreatitis, or suspicious pancreatic cysts.
How the secretin test works is simple. You get an IV injection of synthetic secretin in a clinic. Blood or pancreatic fluid samples are collected before and after the injection to measure how much bicarbonate or digestive enzymes the pancreas releases. If the pancreas responds poorly, it suggests chronic pancreatitis or reduced pancreatic function. If a gastrinoma causes excess acid, secretin can cause a spike in gastrin, which helps doctors identify the tumor.
When you might need the test
Doctors order a secretin test when symptoms and imaging don’t give a clear answer. Think ongoing abdominal pain, unexplained weight loss, fatty stools, or repeated pancreatitis. It’s also used during endoscopic procedures to get clearer pancreatic fluid samples or during specialized imaging to find small tumors.
Practical tips and safety
The test is usually safe. Side effects are rare but can include nausea, flushing, mild abdominal cramps, or a brief drop in blood pressure. Tell your provider about allergies, pregnancy, or heart problems before the test. You’ll likely be asked to fast for a few hours beforehand and to stop certain medications that affect acid or pancreatic secretions—follow those instructions closely.
If you’re worried about pancreatic disease, the secretin test is one option among blood tests, CT, MRI, and endoscopic ultrasound. Secretin can give useful functional information that imaging alone sometimes misses. Ask your doctor which test fits your case and how results will change treatment—whether that means enzyme replacement, diet changes, or tumor evaluation.
For people researching medications and supplements, remember secretin is a diagnostic tool, not a daily treatment you can buy. Don’t try to source hormone injections online. Always work with a qualified clinic for testing and interpretation. If you have questions about results or next steps, a gastroenterologist or pharmacist can explain options, side effects, and lifestyle steps to protect pancreatic health.
After the test, results usually come in days to a week depending on the lab and clinic. A clear response means your pancreas can secrete bicarbonate normally; a weak response points toward chronic pancreatic damage or duct obstruction. If results are unclear, doctors pair secretin data with imaging and stool or blood tests that show enzyme levels and nutritional status. Bring a list of medications and recent imaging when you meet your doctor so they can compare. Ask specific questions: could this explain my weight loss, do I need pancreatic enzymes, or should we look for a tumor? Knowing these next steps makes the test useful, not just a number on a report. Follow up as advised.
