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Stool culture

Stool contains bacteria that are part of the digestive system's normal flora. As such, the presence of bacteria in stool cultures is expected. However, certain strains of bacteria cause infections that lead to symptoms of varying intensity, such as diarrhea.

In addition to bacteria, a stool culture can identify other microbes, such as fungi. Other tests may be performed along with the stool culture to detect the presence of parasites (e.g., intestinal worms) or their eggs. The test may need to be repeated several times.

What is the purpose of this test?
  • To identify the microbe responsible for a gastrointestinal infection
  • To determine the right treatment for the infection
  • To confirm that the treatment for an infection has been effective
How to prepare? Certain products or medications may need to be discontinued for a few days or weeks before stool samples can be taken. It is recommended to consult a health care professional for more information and carefully follow the instructions given by your healthcare provider and the analysis laboratory.

The following are examples of products or medications that may require discontinuation prior to sampling:

  • Heartburn medication (e.g., Gaviscon, Tums)
  • Medication for diarrhea (e.g., loperamide [Imodium], attapulgite [Kaopectate], bismuth [Pepto Bismol])
  • Medication for constipation (e.g., mineral oil, senna [Senokot])
  • Antibiotics, antifungals, or antiparasitics
  • Barium meal or enema
Optimal result Normal or negative
How is it done? A stool sample must be provided for analysis. It must meet the following criteria:
  • Must be stored in the container provided for the test
  • Can be solid or liquid
  • May contain blood or mucus
  • Must not contain urine, toilet paper, or toilet water
  • Must not have been in direct contact with sanitary protection (e.g., a diaper) or the toilet bowl

Here are the recommended steps:

  • Urinate before collecting the stool.
  • Collect the sample on a clean, dry surface, such as the bottom of a shallow pan or a sheet of plastic wrap.
  • Transfer a small amount of the stool into the specimen container (about the size of a hazelnut).
  • Label the container or put it in a labelled plastic bag.
  • Wash your hands.
  • Take the sample to the laboratory as soon as possible.
How long before I get the results? Results are usually ready in a few days. It may take longer to receive your results.

Understanding the result

An abnormal or positive result means that the types of bacteria likely causing the infection have been identified. A normal result means that the sample contains no abnormal bacteria or organisms.

What you should know before going for this test

When you go in for a blood test or any other medical exam, it's always a good idea to bring a complete list of any prescriptions, over-the-counter medications, or natural health products you're taking. Unless otherwise advised, it's best to take your medications as usual on blood test days. If in doubt, don't hesitate to talk to your healthcare professional.

© Copyright Vigilance Santé

The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.

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