Your bowel screening test came back positive

What the result actually means

The test found traces of blood in the sample. That is all it found. It cannot tell where the blood came from, and blood in the bowel has a long list of ordinary explanations: a haemorrhoid, a small tear, inflammation, a harmless polyp that happened to be bleeding that week.

The numbers are worth holding onto. Of the people who have a positive result and go on to a colonoscopy, about one in 29 turns out to have bowel cancer. Adenomas are found far more often. An adenoma is a polyp that could have become cancer if it had been left alone, and it is removed there and then. The rest have another explanation, or nothing is found at all.

So the usual outcome of a positive screening test is either nothing or a polyp being taken out before it ever became a problem. That second outcome is not a near miss. It is the program working exactly as designed.

What happens next

A positive result means a colonoscopy. The referral usually comes from your GP, who will have received the result at the same time you did.

Tell whoever you book with that the referral follows a positive screening test, and ask your GP to write it on the referral. It changes how the appointment is prioritised.

The colonoscopy itself is an examination of the whole large bowel under sedation, usually 20 to 45 minutes, with anything suspicious removed during the same procedure. There is a full description of what it involves, including the preparation and the costs, on a separate page.

How soon it should happen

The screening program's own performance framework sets a maximum of 30 days between referral and colonoscopy after a positive result. Reality falls well short of that. The national median time from a positive test to diagnostic assessment is around 62 days, and waits in parts of the public system run considerably longer. Around one in seven positive screens has no assessment recorded at all, which is the more serious problem.

It is worth saying plainly, because the wait is where most of the distress sits, that Cancer Council Australia's guidance notes there is no evidence that prognosis worsens if the colonoscopy happens within 120 days of a positive test. The argument for moving quickly is a real one, but it is mostly about not leaving someone frightened for four months, rather than about the cancer changing in that time.

What does matter is that the colonoscopy happens at all. If weeks pass and nothing has been booked, chase it. Ring your GP, ring the rooms and do not assume that silence means the result turned out to be nothing.

The one mistake to avoid

Bleeding from a polyp or a cancer is intermittent. A second kit taken a week later can easily come back clear without anything at all having changed, and a clear second result then feels like permission to let the matter drop.

In a study of more than 300,000 people with a positive faecal test, about seven per cent repeated the kit instead of going on to colonoscopy. Three quarters of those repeat tests came back negative, and most of that group never had a colonoscopy within the year. Among those who did eventually get scoped after a repeat test, 4.3 per cent turned out to have bowel cancer.

In the group who never had a colonoscopy at all, only 0.1 per cent had a cancer recorded. That lower number is not reassurance. It is what happens when nobody looks: a cancer is only counted once it is found, and in that group it was found later, by which time it had declared itself some other way.

One positive test is enough. After it there are only two reasonable endings: a colonoscopy or a considered decision with your doctor that a colonoscopy is not appropriate for you. A second kit is neither.

If you also have symptoms

A screening test is a test for people who feel well. If you have had bleeding, a change in bowel habit lasting more than a few weeks, unexplained weight loss, persistent abdominal pain or iron deficiency, say so, because that changes the urgency and sometimes the test.

The same applies in reverse. If you have symptoms and a screening test came back clear, that clear result rules nothing out. See your GP about the symptoms regardless.

A/Prof Kariyawasam sees patients with a positive screening test promptly. Phone the rooms and say that is the reason for the referral.

Where a positive screening test is followed up in Sydney

A/Prof Viraj Kariyawasam is a consultant gastroenterologist and hepatologist whose work includes bowel cancer screening and surveillance. Positive screening results are seen in Norwest, Rouse Hill, Pennant Hills and Macquarie Park.

The colonoscopy that follows is performed at Norwest Private Hospital, Macquarie University Hospital and Pennant Hills Day Surgery. A referral from your GP is needed for a consultation.