Exocrine pancreatic insufficiency (EPI) develops when the pancreas can’t make enough digestive enzymes to allow the absorption of crucial nutrients from food. This can lead to malnutrition and other health problems. Research hasn’t confirmed the prevalence of EPI in the general population, but it tends to be most common in adults with chronic pancreatitis or cystic fibrosis.
Early diagnosis of EPI is crucial for effective treatment in the form of pancreatic enzyme replacement therapy (PERT). But the tests for EPI often have to balance cost-effectiveness, invasiveness, and accuracy, and doctors often misdiagnose EPI due to more common conditions that cause similar symptoms.
Symptoms and Causes of EPI
Before doctors request EPI testing, they’ll ask about symptoms, family and medical history, how much alcohol you consume, and whether you have a history of smoking. A family history of pancreatitis can increase your risk of EPI, as well as regular alcohol consumption and tobacco smoking.
EPI’s inability to break down dietary fat results in steatorrhea, or fatty, oily, pale, bulky, smelly stools. They may also be hard to flush because they float or stick to the toilet. Other EPI symptoms include:
Abdominal discomfort
Excess gas
Bloating
Muscle cramps
Unwanted or unexpected weight loss
Rarely, EPI may cause vision difficulties at night or bone issues, including low bone density and fragile bones that break easily.
It can take years to properly diagnose EPI. A broad range of common conditions have symptoms that resemble those of EPI, and many available tests can’t separate EPI from other ailments that cause the same symptoms. A person with EPI might also have another issue, further complicating the diagnosis.
Common health problems that can cause overlapping symptoms with EPI include:
If you already have a diagnosis for one of these conditions, previously had intestinal surgery, or have a genetic disease that affects how your gut secretes digestive fluids (like Zollinger-Ellison syndrome), the American Gastroenterological Association’s clinical guidelines suggest that a doctor consider testing you for EPI.
Rarer causes that are difficult to distinguish from EPI include deficiency of an enzyme called disaccharidase, bile acid diarrhea, and infectious causes like giardiasis.
Exocrine pancreatic insufficiency impacts your digestive system, and it can also cause symptoms in other parts of your body.Everyday Health
Types of EPI Tests
Doctors diagnose EPI using a range of stool tests, blood tests, and sometimes scans. But a diagnosis may be challenging. No single test can do it, and doctors often use the results of multiple tests as part of an overall clinical picture that includes symptoms and signs of malabsorption and malnutrition. Testing is just one part of the EPI puzzle that your healthcare team will have to solve, but it still provides essential information.
Stool Tests
A stool, or fecal elastase-1 (FE-1), test is often the first performed for EPI given the hallmark symptom of steatorrhea. The healthcare provider gives you a container for a stool sample, and you’ll need to provide a semisolid or solid stool. This tests levels of the pancreatic enzyme elastase, which supports protein digestion, in the intestines. This enzyme survives passing through the digestive system, so it shows up in stools. Low levels in the stool suggests you may have EPI.
FE-1 testing is accurate at showing severely impaired pancreas function, such as for children with cystic fibrosis. But while FE-1 isn’t as expensive or invasive as other tests, it often gives false-positive or false-negative results. For example, it’s also unsuitable for use when a person has particularly watery stools, because the FE-1 content may be diluted, potentially giving a false-positive result. An FE-1 test also isn’t effective at detecting mild EPI. A doctor may elect to start PERT without this type of test, especially if a person has underlying pancreas issues and symptoms like steatorrhea.
Measuring the fat content of stools through a fecal fat test may show how much fat the body is unable to digest. But doctors rarely recommend this test during routine screening for EPI, because a person needs to eat a specific, moderate-fat diet containing definite fat content for five days beforehand. This places a high burden on the patient.
Fecal fat testing plays a role in clinical research more than in practical medicine. But doctors might suggest a fecal fat test if a person isn’t showing a good response to PERT.
Blood Tests
Healthcare professionals may collect a blood sample to check levels of the fat-soluble nutrients A, D, E, and K and other minerals. People with EPI have difficulty processing fats, so these levels may be lower for them. These tests may help doctors identify malnutrition.
Blood tests can also measure trypsinogen, the pancreatic enzyme that converts to trypsin. This can be a helpful way for doctors to check how you’re responding to PERT treatment, as FE-1 levels don’t change when you take pancreatic enzymes from outside the body, but trypsin levels do.
Pancreatic Function Tests
An endoscopic pancreatic function test (ePFT), also known as a secretin pancreatic function test, is the most accurate way to directly test how the pancreas is working. A gastroenterologist inserts a flexible telescope into a person’s mouth while they’re under anesthesia and passes it down through the digestive system; this process is known as an endoscopy. The gastroenterologist administers a hormone called secretin that usually triggers the release of digestive enzymes, then collects pancreatic juice every 15 minutes for an hour to measure the concentration of a compound called bicarbonate. A pancreas will make enough bicarbonate if it is working well.
Despite its accuracy, ePFT is infrequently done and usually limited to specialized centers because it's complex and time-consuming. The American Gastroenterological Association says that direct pancreatic function tests (ePFTs included) are promising but not widely available in the United States. The American Pancreatic Association further states that these tests are great at diagnosing early chronic pancreatitis but are often saved for patients being evaluated for chronic abdominal pain and suspected chronic pancreatitis.
Imaging Tests
These can’t directly diagnose EPI, but doctors will often carry out a range of imaging tests to rule out or identify underlying pancreatic problems, such as pancreatic cancer, advanced pancreatitis, or a shrinking pancreas. These may include a computed tomography (CT), magnetic resonance imaging (MRI) scan, or endoscopic ultrasound (EUS).
During an EUS, along with capturing imaging of the pancreas, the gastroenterologist may also collect a biopsy using a fine needle attached to the end of the scope if they find any tumors or cysts.
Next Steps After EPI Diagnosis
The challenge with EPI is a timely diagnosis. But it's crucial so that people can access the right nutritional support and start medications, which can greatly improve the outcome of treatment.
The right dosage for PERT can be tricky to determine; the number of capsules you’ll need to take is highly individualized. The dosage may need to change according to your symptoms. You’ll need to work closely with your care team to determine how much you need and to measure their effectiveness for nutrient absorption and enzyme levels.
Your doctor might suggest the following treatment and management options:
Take supplements to replace fat-soluble vitamins A, D, E, and K, which the body may have problems absorbing if it can’t digest fats.
People may need further treatment if other conditions like pancreatitis, cystic fibrosis, pancreatic cancer, diabetes, or inflammatory bowel disease are causing EPI. Work with your doctor and dietitian to find the best treatment for you if you receive an EPI diagnosis.
Questions to Ask Your Doctor
What are the most common tests used to diagnose EPI?
How accurate are these tests in diagnosing EPI? Would I benefit from a second opinion?
How should I prepare for the EPI test you’re recommending?
How do I interpret the results of the EPI tests?
What are the next steps for diagnosis and treatment if testing shows an EPI diagnosis?
What’s the best treatment for my anatomy and health needs?
What dietary changes should I expect?
The Takeaway
Exocrine pancreatic insufficiency (EPI) can be challenging to diagnose because of symptoms that overlap with other conditions.
Fecal elastase (FE-1) testing is the most common first test, but it can produce false-negative and false-positive results. Blood tests can diagnose EPI-linked nutrient deficiencies and check levels of EPI-linked proteins in the blood.
Doctors may also use imaging to identify pancreatic or gastrointestinal diseases that could be causing or are related to EPI.
Discuss EPI symptoms like steatorrhea, gas, bloating, weight loss, or digestive discomfort with a healthcare professional.
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Resources
Ghodeif AO et al. Pancreatic Insufficiency. StatPearls. January 16, 2023.
Whitcomb DC et al. AGA Clinical Practice Update on the Epidemiology, Evaluation, and Management of Exocrine Pancreatic Insufficiency: Expert Review. Gastroenterology. November 2023.
Exocrine Pancreatic Insufficiency (EPI). Cleveland Clinic. June 10, 2021.
Pandey A et al. A Review of Exocrine Pancreatic Insufficiency in Children beyond Cystic Fibrosis and the Role of Endoscopic Direct Pancreatic Function Testing. Current Gastroenterology. February 19, 2025.
Whitcomb DC et al. AGA Clinical Practice Update on the Epidemiology, Evaluation, and Management of Exocrine Pancreatic Insufficiency: Expert Review. Gastroenterology. September 20, 2023.
Yuying Luo, MD, is an assistant professor of medicine at Mount Sinai West and Morningside in New York City. She aims to deliver evidence-based, patient-centered, and holistic care for her patients.
Her clinical and research focus includes patients with disorders of gut-brain interaction such as irritable bowel syndrome and functional dyspepsia; patients with lower gastrointestinal motility (constipation) disorders and defecatory and anorectal disorders (such as dyssynergic defecation); and women’s gastrointestinal health.
She graduated from Harvard with a bachelor's degree in molecular and cellular biology and received her MD from the NYU Grossman School of Medicine. She completed her residency in internal medicine at the Icahn School of Medicine at Mount Sinai, where she was also chief resident. She completed her gastroenterology fellowship at Mount Sinai Hospital and was also chief fellow.
Adam is a freelance writer and editor based in Sussex, England. He loves creating content that helps people and animals feel better. His credits include Medical News Today, Greatist, ZOE, MyLifeforce, and Rover, and he also spent a stint as senior updates editor for Screen Rant.
As a hearing aid user and hearing loss advocate, Adam greatly values content that illuminates invisible disabilities. (He's also a music producer and loves the opportunity to explore the junction at which hearing loss and music collide head-on.)
In his spare time, Adam enjoys running along Worthing seafront, hanging out with his rescue dog, Maggie, and performing loop artistry for disgruntled-looking rooms of 10 people or less.
