What can be detected in a stool sample?

Was kann in einer Stuhlprobe nachgewiesen werden?

Everybody has it, yet we don’t like talking about it – bowel movements. But did you know that a stool sample can tell you a lot about your health? It is important to check your stool regularly because its texture, shape, colour, and even smell can give you an indication of your health. But this is not where the insight ends. Sending a stool sample into the lab can give you much more information than you might expect. In this article, we would like to inform you about the conditions a stool sample can diagnose. 

Ist mein Stuhlgang gesund?

First, it is important to define what healthy stool actually looks like. Generally, stool has a rather soft texture and a brownish colour. Stool consists of around 75% water and around 25% solid matter and consists of indigestible food, dead bacteria, and inorganic substances. On average, it takes food three days to pass through your digestive system, resulting in a bowel movement. In case your stool has a black or even red colour, you should visit a doctor as this indicates gastrointestinal bleeding. Grey stool can be an indicator of liver problems, while yellow, sour-smelling stool can indicate that your intestines do not absorb and digest fat properly.

Welche Krankheiten können in einer Stuhlprobe nachgewiesen werden?

As mentioned earlier, stool can not only be visually expected- it is also possible to take stool samples and send them to a lab. Stool samples can help diagnose a wide variety of diseases, such as:

  • Inflammatory bowel disease
  • Malabsorption von Fett
  • Pankreasinsuffizienz
  • Blutungen im Verdauungstrakt

Entzündliche Darmerkrankung

Anhand einer Stuhlprobe lässt sich der Calprotectinspiegel im Stuhl messen. Calprotectin ist ein Protein, das in den weißen Blutkörperchen vorkommt. Es ist bekannt für seine starken antimykotischen und antibakteriellen Eigenschaften. Wenn eine Entzündung auftritt, steigt Calprotectin an. Seine Konzentration steht in direktem Zusammenhang mit der Intensität der Entzündung. Je stärker die Entzündliche Darmerkrankung ausgeprägt ist, desto höher sind die Calprotectinwerte.


In case your digestive system cannot absorb or digest fat in your food properly, you can detect this with a stool sample. However, keep in mind that a stool sample only detects if you have abnormally high amounts of fat in your stool, not why. Therefore, if this diagnosis occurs, further testing is required.


When sending a stool sample to the laboratory, it is also possible to check for pancreatic insufficiency. With this test, elastase in the stool will be measured. Elastase is an enzyme that is made in an organ in your upper abdomen, called your pancreas. When your pancreas is healthy, a sufficient level of elastase will be found in your stool sample. If the level is too low, it can be an indicator for pancreatic insufficiency.

Blutungen im Verdauungstrakt

There are two types of stool tests that are used to test for colorectal cancer; the fecal occult blood test (FOBT) test that focuses on finding hidden (occult) blood in the stool sample, and the stool DNA test that detects abnormal DNA associated with colon polyps or cancer. Interested? Homed-IQ now offers a FOBT test that can be easily taken from home before being sent to a laboratory for analysis.

Welche Infektionen können in einer Stuhlprobe nachgewiesen werden?

Generally speaking, a stool sample can help diagnose three types of infections:

  • Würmer
  • Parasiten
  • Bakterien

Würmer in der Stuhlprobe

Ob Sie es glauben oder nicht, aber Würmer sind eine Infektion, die nicht nur Tiere bekommen können. Man kann sich auf verschiedene Weise mit Würmern anstecken, z. B. auf Reisen durch ein tropisches Land oder bei der Arbeit mit Kindern in einer Kindertagesstätte. Zu den Symptomen einer Wurminfektion können gehören:

  • Durchfall
  • Nausea or vomiting
  • Schmerzen im Unterleib
  • Significant weight loss
  • Ermüdung

Krankheitserregende Bakterien in der Stuhlprobe

Sending a stool sample to the laboratory can reveal a variety of bacteria, such as:

  • Escherichia coli 0157:H7 (kann in rohem und nicht durchgegartem Rindfleisch gefunden werden)
  • Shigellen (können in verunreinigtem Wasser oder verunreinigten Lebensmitteln gefunden werden)
  • Campylobacter (kann in rohem und nicht ausreichend gegartem Geflügel vorkommen)
  • Salmonellen (können in rohem Geflügel oder rohen Eiern gefunden werden)

Parasiten in der Stuhlprobe

It is also possible to detect parasites and/or their eggs in stool samples. Common organisms found in a stool sample are Blastocystis or Giardia. There is no direct link between Blastocystis and any diseases, but it is noticeable that patients with Blastocystis often suffer from diarrhoea. Giardia also has no direct link to diseases, and most people also do not experience any symptoms. However, if patients do experience symptoms, they experience a wider variety of symptoms compared to Blastocystis. Symptoms of Giardia are, among others:

  • Magenschmerzen
  • Fatty stool
  • Gas/flatulence
  • Ermüdung

Was können Stuhltests nicht diagnostizieren?

So far, we have highlighted all the diseases and infections that an examination of a stool sample can detect, but this examination also has its limits. Stool samples do not offer a complete picture of your overall health. A stool sample cannot detect the following:

  • Gluten intolerance 
  • Andere Nahrungsmittelüberempfindlichkeiten
  • Dünndarmfehlbesiedlung (DDFB)
  • Nahrungsmittelallergien
  • Candida-Überwucherung
  • Dysbiose
  • Undichter Darm

The examination of a stool sample is not considered a scientifically valid way to diagnose gluten sensitivity, lactose intolerance, or any other sort of food intolerance/sensitivity. Therefore, it is important to point out that examined stool samples cannot provide any kind of evidence-based recommendations about which kind of diet you should follow.


Duker, T. (2019, April 5). What Can a Stool Test Diagnose? US Health News. Aufgerufen am 1. April, 2022, from https://health.usnews.com/health-news/blogs/eat-run/articles/what-can-a-stool-test-diagnose

Falconer, A. (2021, July 20). What can be detected in a stool sample? (UK). Healthpath. Aufgerufen am 1. April, 2022, from https://healthpath.com/gut-health/what-can-be-detected-stool-sample-uk/

Piedmont. (n.d.). What Your Stool Says About Your Health | Piedmont Healthcare. Retrieved April 1, 2022, from https://www.piedmont.org/living-better/what-your-stool-says-about-your-health#:%7E:text=It%20may%20sound%20gross%2C%20but,health%20problems%2C%20such%20as%20cancer.