Stool
Digestion
Test digestive capacity via stool. Analyzes proteins, fats, and carbohydrates.
€ 65,00
All tests
Gut · Stool
Color (feces)
The color of the stool; depends mainly on diet and bile, and describes the stool at the time of sample collection.
At a glance
- Measured in stool
- In 1 test panel
- No special preparation
Explanation
Color (feces): what is measured?
The laboratory describes the color of the stool sent in. The brown color comes from breakdown products of bile. Diet, iron tablets and the speed of passage through the gut change the color. It is a description, not a measurement of a substance.
What can it detect?
- A change in color that may fit diet, medicines, fast passage through the gut or too little bile in the gut
Result
What does the result mean?
What the result tells you
Brown in various shades is the usual color. Green or yellow stool often fits green vegetables or fast passage through the gut, as with diarrhea. Black stool is often caused by iron tablets, licorice or blueberries; without such an explanation it may fit blood from the stomach or gut, and prompt assessment by the GP is needed. Red can be caused by beets or by blood. Very pale, gray or putty-colored stool may fit too little bile in the gut, for example due to gallstones.
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
Color (feces): test panels
Color (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.
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 resultsMore explanations
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