Stool
4D Basic Package
Comprehensive basic analysis of intestinal health, including activity measurements and biomarkers.
€ 625,00
All tests
Gut · Stool
Fats (feces)
Undigested fat in the stool; may point to poor fat digestion, but a single sample is unreliable.
At a glance
- Measured in stool
- In 5 test panels
- No special preparation
Explanation
Fats (feces): what is measured?
Fat from food is broken down in the small intestine, with the help of bile and an enzyme from the pancreas (lipase), into fatty acids that the gut absorbs. The laboratory determines how much undigested fat (neutral fat) is still in a stool sample. A lot of undigested fat mainly fits a shortage of digestive juices from the pancreas.
What can it detect?
- A sign of poor fat digestion (fatty stool, steatorrhea)
- A sign of too little production of digestive juices by the pancreas (exocrine pancreatic insufficiency)
Result
What does the result mean?
Fats (feces) too high
A raised amount of fat can be caused by a fatty meal, diarrhea or weight-loss medicines that block fat absorption. A persistently raised value may fit too little production of digestive juices by the pancreas (exocrine pancreatic insufficiency), for example due to chronic inflammation of the pancreas, or a condition of the small intestine. Symptoms that go with it are fatty, shiny or foul-smelling stool that is hard to flush away and unintended weight loss. Rarely: cystic fibrosis or a tumor of the pancreas.
Fats (feces) too low
Little or no undigested fat is the normal result and fits good fat digestion. A low value has no further meaning. With a low-fat diet in the days before sample collection, a fat digestion problem can be missed.
After an abnormal result
Without symptoms, an abnormal result from this test usually needs no follow-up. With symptoms that fit poor digestion, the GP can request pancreatic elastase in the stool or a blood test for celiac disease, and if needed refer you to a gastroenterologist or internist (specialist in internal medicine).
Reliability
How reliable is the test?
Food remnants in a single stool sample mainly say something about what you have eaten and how quickly the food passed through the gut. How well the result shows or rules out poor digestion has not been well studied, neither in people without symptoms nor in people with bowel symptoms. If poor fat digestion (malabsorption) is suspected, the specialist may have fat measured in stool collected over a few days. For pancreatic function, pancreatic elastase in the stool has been studied better.
What can affect the result?
- Food in the days before sample collection (fat, meat, raw vegetables, legumes, dairy, sugars) largely determines the result.
- Diarrhea or, on the contrary, constipation changes the result, because the speed through the gut determines how much is digested.
- One stool sample gives a snapshot; the composition differs from day to day.
- Medicines such as laxatives, antibiotics, stomach acid inhibitors, pancreatic enzymes and weight-loss medicines that block fat absorption (orlistat) affect the result.
Who it is for
Who is the test useful for?
Useful for
Because diet strongly determines the result, this test says little in people without symptoms, and even with symptoms it does not identify a cause. With symptoms that may fit poor digestion, such as long-lasting fatty or mushy stools, unintended weight loss or long-lasting diarrhea, testing through the GP is the right route. Pancreatic elastase in the stool and a blood test for celiac disease are then more targeted first tests. With blood in the stool, unintended weight loss or new bowel symptoms after the age of 50, this test is no substitute for a visit to the GP.
How common is it?
There are no Dutch figures on how often an abnormal result for these tests occurs. Bowel symptoms themselves are common: according to the guideline, irritable bowel syndrome affects about 4 in 100 adults. Conditions in which food is truly poorly digested, such as chronic inflammation of the pancreas, are much rarer.
Dutch medical specialists' guidelines (FMS) on irritable bowel syndrome (NHG and NVMDL) and chronic pancreatitis
Get tested
Fats (feces): test panels
Fats (feces) is part of these test panels. You order online and have your blood drawn at a collection point or collect the sample at home.
Stool
4D Orientation package
Orientation of basic microbial distribution in the gut, including main groups and activities.
€ 220,00
Stool
4D Specialist package
Comprehensive gut health analysis for patients with complex health problems.
€ 975,00
Stool
4D Extended package
In-depth investigation of gut health, biodiversity, and biomarkers for persistent complaints.
€ 750,00
Stool
Bile Acids
Analysis of fats, water content, proteins, starch, sugar, and bile acids in stool.
€ 95,00
Evidence
Sources
This explanation is based on Dutch guidelines and independent information. It is general information, not a diagnosis. Discuss an abnormal result with your GP.
More about risks and results- FMS Richtlijnendatabase: Prikkelbaredarmsyndroom, module Diagnostiek PDS
- NHG-Standaard Prikkelbaredarmsyndroom (PDS)
- NVKC, allesovertesten.nl: Elastase
- NVKC, allesovertesten.nl: Trypsine
- Thuisarts.nl: Ik heb diarree
- FMS Richtlijnendatabase: Somatische complicaties van risicovol alcoholgebruik, module Chronische pancreatitis
More explanations
Other tests: Gut
- Acetate and propionate production
- Acetate- and propionate-forming bacteria
- Acetic acid (feces)
- Acetic acid, relative (feces)
- Akkermansia, activity
- Alpha-1 antitrypsin (feces)
- Anti-gliadin IgA (feces)
- Anti-transglutaminase IgA (feces)
- Aspergillus fumigatus (feces)
- Aspergillus niger (feces)
- Bacteroides group, activity
- Beta-defensin 2 (feces)