Receiving a letter saying your bowel screening test is “positive” can feel worrying. Many people immediately fear the worst. However, a positive result does not mean you have bowel cancer. It simply means that small traces of blood were detected in your stool sample, and further investigation is recommended to find the cause.
In Australia, the National Bowel Cancer Screening Program uses a simple at-home stool test called the immunochemical faecal occult blood test (iFOBT). This test detects microscopic blood that cannot be seen with the naked eye.
Understanding what a positive result means—and what happens next—can help reduce anxiety and ensure you take the right next steps.
What Can Cause a Positive Test?
A positive bowel screening test means blood was found in one or both stool samples. This blood may come from several different conditions, many of which are not cancer. ()
Common causes include:
- Colonic polyps
- Haemorrhoids (piles)
- Inflammation of the bowel
- Diverticular disease
- Minor bleeding from the digestive tract from small blood vessels
Importantly, screening tests are designed to detect potential problems early, before symptoms develop. In fact, most people with a positive test do not have bowel cancer.
The purpose of the screening program is to identify people who need further investigation, usually with a colonoscopy.
The Next Step: Seeing your GP
If your screening test is positive, the first step is to make an appointment with your GP.
Your doctor will:
- Review your screening result.
- Ask about symptoms, medications and family history.
- Discuss the need for further testing.
In most cases, your GP will refer you to a gastroenterologist or colorectal specialist for a colonoscopy.
It’s important not to ignore a positive result. Following up promptly ensures that any underlying condition can be identified and treated early if necessary.
Why is a Colonoscopy Recommended?
A colonoscopy is the most accurate test for examining the large bowel.
During the procedure:
- A thin flexible camera is passed through the rectum to inspect the colon.
- The specialist looks for polyps, inflammation or other abnormalities.
- If polyps are found, they can often be removed during the procedure.
- If bowel cancer is detected, it is usually detected early where treatment is most effective
Polyps are important because some can develop into bowel cancer over time. Removing them early can prevent cancer from developing.
Most colonoscopies in Australia are performed under twilight sedation, meaning patients are comfortable and usually remember very little of the procedure.