The human digestive tract is susceptible to a number of diseases. These may occur due to the germs such as bacteria, viruses, fungi, etc., that may enter the digestive tract. Stool culture tests are used to identify bacteria that might be causing a particular disease of the digestive tract.

It is done by asking the patient to deposit a stool/faecal specimen in a sterile container, which is then sent to the pathology laboratory for diagnosis.

In a stool culture, the laboratory staff will add certain substances to the stool sample, meaning, “grow a culture” of the disease-causing germs that may be living in your stool. This will help to find out whether the particular stool sample is healthy, i.e., free of pathogens, or contains bacteria, viruses, fungi, parasites, or any other agents that can cause disease.

The stool sample is “smeared” on culture plates. These plates contain a medium that acts as a promoter of growth for the living germs in the stool.

Once this is done, the sample is then stained with certain dyes to identify the type of pathogens present in the sample, or it is observed under the microscope for a better understanding. These steps help to confirm the diagnosis.

The test is done if any kind of gastrointestinal infection is suspected. There may be a variety of symptoms such as - Nausea, Vomiting, Diarrhoea, Bloody diarrhoea/ dysentery, Persistent high fever, loss of appetite, and abdominal pain.

Other names of stool culture test

• Stool sample culture testing
• Stool culture test
• Faecal culture
• Faecal sample culture test
• Stool bacterial culture

What does this test measure, and who is the stool culture test prescribed for?

A stool culture is prescribed when the natural/normal flora of the digestive tract is disturbed. There are a number of natural bacteria present in the gut that are useful and play an important role in our health. These are not tested for. When disease-causing pathogens enter the system, it leads to disturbances such as abdominal cramps, diarrhoea, nausea, vomiting, etc. A few of the pathogens are listed below:

1. E. coli
2. Salmonella typhi
3. Shigella
4. Campylobacter
5. Clostridium
6. Entamoeba
7. Ascaris

Bacteria

1. Escherichia coli:

E. coli may cause food poisoning.

1. Campylobacter jejuni

It causes a number of symptoms, such as bloody diarrhoea, fever, nausea, and vomiting.

1. Bacillus cereus

It causes a severe type of food poisoning.

The sample for Stool Culture to be collected for this test is a stool or human faeces. A fresh sample is collected in a sterile container and then tested for diagnosing the disease.

Test Preparation

Generally, no prior preparation is needed for a stool culture test procedure.

You should let your doctor know if you have recently consumed impure water, food that had gone bad or had a barium enema.

A fibrous diet is recommended prior to the day of the collection of the stool sample if you suffer from constipation.

Test inclusions: What parameters are included?

A stool culture test is performed when there is a doubt that an individual may be suffering from gastrointestinal-related problems. In this method, a stool sample of the patient is collected in a clean container. It is then tested for the presence of disease-causing pathogens.

These could be:

a) Bacteria

It is examined using the following parameters:

• Colour
• Consistency
• Amount
• Shape
• Odour
• Presence of blood
• Presence of mucus
• Presence of bile

The presence of blood, mucous, bile, etc., in stool, are abnormal findings.

If these substances are present in the stool, it indicates an underlying medical condition.

For example, blood in the stool could indicate that the person is suffering from bleeding in the intestines due to an infection or inflammation like ulcerative colitis.

Mucus in the stool could be a sign of Crohn’s disease.

Bile in the stool could be a sign of bile acid diarrhoea.

How frequently should you take this test?

This test should be done when you are experiencing gastrointestinal system-related problems, such as vomiting, diarrhoea, abdominal cramps, fever, etc., for more than 2-3 days.

Routine testing is rarely needed.

Typhoid, Colitis, Bacterial gastroenteritis, Amoebiasis