Stool tests are used to check for possible bowel cancer and to look for causes of gastrointestinal illness.
Types of stool tests
Stool specimens are tested in the laboratory in a variety of ways depending on their purpose. These tests are also sometimes called faecal tests.
Faecal occult blood test
Faecal occult blood tests, or FOBTs, are used to test healthy people for possible bowel cancer. The test looks for tiny amounts of blood in the faeces. Anyone who has blood in their faeces would then go to have more testing to see whether the cause is cancer or something else.
Some Australians aged between 50 and 74 years are eligible for free FOBT test through the National Bowel Cancer Screening Program. Currently, a free FOBT is sent to Australians turning 50, 54, 58, 60, 62, 64, 66, 68, 70, 72 and 74 years of age. By 2020, all Australians aged 50 to 74 will be offered the test free every two years.
If you’re not eligible for a free test, your doctor can suggest other options. For more information, call the Cancer Council Helpline on 13 11 20.
Stool culture helps identify bacteria and parasites that might cause problems like diarrhoea. A stool culture test can also detect the presence of Helicobacter pylori bacteria, which are associated with stomach ulcers and stomach cancer.
How do I collect samples?
Stool samples for FOBTs are easily collected in the privacy of your own home. Because you are sampling regular bowel movements, there are few potential complications.
But you need to be careful with stool samples for culturing. They need to be handled carefully to keep your hands clean and avoid passing on an infection. You also need to make sure you don't contaminate the sample with urine or toilet paper.
Collect your samples in sterile vials, which your doctor will have given you. Store them in the fridge, well away from food, then take them to your doctor or to the pathology lab as soon as possible. If there's going to be a delay, talk to your doctor about it.
What do my results mean?
Around 1 in every 14 people has a positive FOBT test – that is, blood is found in their faeces. A positive result does not necessarily mean you have bowel cancer. Other conditions like polyps, haemorrhoids or inflammation can give you positive results.
But if you do have a positive result, you should contact your doctor, who might recommend other tests like a colonoscopy.
If your FOBT is all clear, that's good. But it doesn't mean you'll never develop bowel cancer. If you're over 50, you should have regular screening every two years.
If you have a stool culture test and it is positive, see your doctor. You might need treatment.
Last reviewed: March 2018