Quick answer: Faecal elastase is an enzyme made by the pancreas, and measuring it in a stool sample gives an indication of how well the pancreas is producing digestive enzymes. A result below 200 µg/g suggests exocrine pancreatic insufficiency (EPI), and below 100 µg/g suggests it is more marked, although watery stool samples can give falsely low results. EPI means fats, and to a lesser extent proteins and carbohydrates, are not fully digested, which can cause pale, greasy, foul-smelling or floating stools, bloating, wind and weight loss. It is more common with chronic pancreatitis, pancreatic surgery, diabetes, coeliac disease and older age. A low result should always be reviewed by your doctor, who can confirm it and decide on pancreatic enzyme replacement. Nutrition then supports digestion and nutrient status.
More and more people now arrive at their first session with a stool test in hand, and faecal elastase is one of the markers that raises the most questions. It is a small number with big implications, so it is worth understanding properly. For a wider view of stool testing, see are gut microbiome tests worth it? and faecal calprotectin explained.
What does faecal elastase measure?
The pancreas has two jobs: it makes hormones such as insulin, and it makes digestive enzymes that break down fats, proteins and carbohydrates in the small intestine. Elastase-1 is one of those enzymes. It passes through the gut largely intact, so the amount in stool reflects how much the pancreas is releasing.
Because the test measures human elastase, it is not affected by pancreatic enzyme capsules, which are usually made from pork enzymes. It is a simple, widely used screening test for exocrine pancreatic insufficiency (EPI).1,2
What is a low faecal elastase level?
Laboratories commonly use these ranges:1
- Above 200 µg/g: normal pancreatic enzyme output is likely.
- 100–200 µg/g: mild to moderate insufficiency is possible.
- Below 100 µg/g: more marked insufficiency is likely.
There is an important catch: if the sample is loose or watery, the elastase is diluted and the result can look falsely low. A borderline result from a diarrhoea sample often deserves a repeat on a formed stool, with your doctor, before conclusions are drawn.
What are the symptoms of pancreatic insufficiency?
When fat is not properly digested, it reaches the colon and changes the stool. Common signs include:2
- pale, bulky, greasy or shiny stools
- stools that float, leave an oily film or are hard to flush
- a particularly strong smell
- bloating, wind and cramping, often an hour or two after meals
- urgency or loose stools after fatty meals
- weight loss despite eating normally
- low levels of fat-soluble vitamins A, D, E and K
Floating stools on their own are not proof of fat malabsorption: trapped gas, often from fermentation, is a more common reason. It is the overall pattern that matters.
When to see your doctor first
- Unintentional weight loss
- Yellowing of the skin or eyes (jaundice), dark urine or very pale stools
- Persistent upper abdominal or back pain
- New diabetes, especially with weight loss, after 50
- Persistent diarrhoea or stools that are consistently greasy
- Blood in the stool or black stools
What causes low faecal elastase?
- Chronic pancreatitis, often linked to long-term heavy alcohol use and smoking.1
- Pancreatic surgery or surgery on the stomach or upper small intestine.
- Cystic fibrosis.
- Diabetes. Reduced elastase is found in a meaningful proportion of people with type 2 diabetes, and more often in type 1.4
- Coeliac disease. In people with coeliac disease who still had diarrhoea despite a gluten-free diet, pancreatic insufficiency was one of the explanations found.3
- Older age. Pancreatic output tends to decline with age.
- Less commonly, a tumour of the pancreas, which is why new symptoms always need medical review.
Sometimes a mildly low result reflects a temporary situation or a sample issue rather than true insufficiency, which is another reason to interpret it with your doctor.
A stool test result you are not sure what to do with?
Let's look at your results, your symptoms and your diet together, so you can have a clear conversation with your doctor about next steps – a free call, with no commitment.
Book your free 15-minute call →How is pancreatic insufficiency managed?
If your doctor confirms EPI, the cornerstone is pancreatic enzyme replacement therapy: capsules taken with meals and snacks containing fat, with the dose adjusted to symptoms and meal size.2 Your doctor will also usually look for the underlying cause, check vitamin and bone status and review other conditions such as diabetes.
Over-the-counter digestive enzymes are not the same as medical enzyme replacement, and they should not be used to mask symptoms that have not been investigated.
How can nutrition support pancreatic insufficiency?
Nutritional therapy can support you alongside your medical team:
- Do not cut fat too far. Current guidance moves away from very low-fat diets, because fat carries energy and essential vitamins. The aim is to digest it better, not to avoid it.2
- Spread food across the day. Smaller, regular meals with a moderate amount of fat each time are often easier to digest.
- Time enzymes well. If enzymes have been recommended, taking them with the first bites and spreading the dose through larger meals often works better than taking them afterwards.
- Check nutrient status. Vitamin D, A, E and K, B12, iron, zinc and magnesium are worth reviewing with your doctor.
- Limit alcohol and stop smoking, as both affect the pancreas.
- Look at the whole picture. Fat malabsorption often overlaps with SIBO, bile acid issues or coeliac disease, so persistent symptoms deserve a broader look.
Frequently asked questions
Can a low faecal elastase result be wrong?
Yes. A watery sample can dilute the enzyme and give a falsely low result. A borderline result is often repeated on a formed stool.
Do digestive enzyme supplements affect the elastase test?
Medical pancreatic enzymes are usually made from pork enzymes, which the test does not detect, so they do not usually change the result. Always tell your doctor what you take.
Why do my stools float?
Floating stools are most often due to trapped gas from fermentation. Stools that are also pale, greasy and hard to flush may point to fat malabsorption and are worth discussing with your doctor.
Can pancreatic insufficiency cause bloating?
Yes. Undigested food reaching the colon is fermented by bacteria, which can cause bloating and wind, often an hour or two after meals.
Should I eat a low-fat diet if my elastase is low?
Not usually. Very low-fat diets can worsen nutrient deficiencies. With your doctor, the aim is to digest fat better, usually with enzyme support, not to cut it out.
References
- Löhr JM, Dominguez-Munoz E, Rosendahl J, et al. United European Gastroenterology evidence-based guidelines for the diagnosis and therapy of chronic pancreatitis (HaPanEU). United European Gastroenterol J. 2017. PubMed: PMID 28344786
- Whitcomb DC, Buchner AM, Forsmark CE. AGA Clinical Practice Update on the Epidemiology, Evaluation, and Management of Exocrine Pancreatic Insufficiency: Expert Review. Gastroenterology. 2023. PubMed: PMID 37737818
- Leeds JS, Hopper AD, Hurlstone DP, et al. Is exocrine pancreatic insufficiency in adult coeliac disease a cause of persisting symptoms? Aliment Pharmacol Ther. 2007. PubMed: PMID 17269988
- Zhang J, Hou J, Liu D, et al. The Prevalence and Characteristics of Exocrine Pancreatic Insufficiency in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis. Int J Endocrinol. 2022. PubMed: PMID 36213198
This article is for educational purposes and is not medical advice. Nutritional therapy does not replace medical care. Always work with your doctor for any persistent or new symptoms and before making changes to your care, medication or supplements.