Stool tests

What is a stool test?

Stool tests examine samples of poo (also called faeces or bowel motions). Stool samples can be tested in the laboratory in a variety of ways, depending on why you are doing the test. These tests are sometimes called faecal tests.

Why might I need to have a stool test?

There are many different reasons why you might be recommended to have a stool test, such as:

• to find the reason for an infection
• to check if you have inflammatory bowel disease
• to check if you are absorbing food properly
• to see if you might have bowel cancer

What type of stool test can look for bowel cancer?

An immunochemical faecal occult blood test, or iFOBT, is used for bowel cancer screening. It tests healthy people for blood in their faeces that may come from bowel cancer. The test can detect tiny amounts of blood that you can’t see. The aim is to find cancers early.

If the test shows you have blood in your faeces, you will need to have more testing to see what is causing it — it’s not always due to cancer.

All Australians aged between 50 and 74 are eligible to do a free iFOBT every 2 years through the National Bowel Cancer Screening Program.

What type of stool test can diagnose an infection?

Stool microscopy and culture

Stool microscopy and culture can identify bacteria, viruses or parasites that might cause gastroenteritis.

Most of the time gastroenteritis gets better by itself and no tests are needed. Your doctor might refer you for one of these tests if you have diarrhoea that lasts more than a few days or contains blood, or if you have recently travelled overseas, or if you may be involved in an outbreak.

If the test shows bacteria or a parasite, you may need to take medicine for it. If nothing is detected on the test but your symptoms continue, see your doctor.

Clostridium difficile stool test

Clostridium difficile (also known as C. diff) is a type of bacteria that can cause diarrhoea after taking antibiotics. It is detected on a stool test.

Helicobacter pylori stool test

Helicobacter pylori is a type of bacteria that can cause stomach ulcers and stomach cancer. It can be detected on several different types of tests, including a stool test.

What types of stool test can check for other health conditions?

There are other stool tests which are sometimes done to diagnose or monitor certain health conditions. Here are some examples:

• Faecal calprotectin — this is a test of inflammation in the bowel. It may help your doctor work out if you have inflammatory bowel disease. If you do, it can also be used to monitor the level of inflammation if you have a flare-up.
• Faecal elastase and fat — these can be tested to check if your pancreas is working properly. Your doctor might ask you to do this test, if there are signs that you are not absorbing food well.

How do I collect a stool sample?

Faecal occult blood test

Stool samples for iFOBTs are easily collected in the privacy of your own home. You will get a free kit in the mail with instructions. This is part of the National Bowel Cancer Screening Program. Once you have done the test, you will need to mail the samples to the laboratory.

Stool tests for infection

Your doctor or pathology collector will give you sterile jars to collect your sample in. Hold a clean plastic container (lined with toilet paper) in the toilet to catch your faeces and then transfer some of it into the sterile jars. Make sure you don’t contaminate the sample with urine or water. If you need to pass urine, do so before collecting your stool sample.

Wear gloves and wash your hands carefully after doing the test to avoid passing on an infection. Discard the remaining contents of the plastic container into the toilet.

You will need to take the sample to the laboratory as soon as possible. You may need to store the sample in the fridge until you deliver it. Talk to your doctor or pathology collector about what to do.

How will I get results of my stool test?

If you have done a faecal occult blood test, you should get your results in the mail about 2 weeks later. Your results will also be sent to your doctor, if you nominated them on the form you sent in with the sample. If your test is positive, make an appointment with your doctor to discuss what to do next.

For any other stool test, you can get the results from your doctor. It’s very important to talk to your doctor about your test results.