The risk of bowel cancer recurrence is highest in the first 2–3 years after treatment, with most recurrences happening within five years. Structured surveillance during this window does two important things: it picks up recurrence early — while it is most treatable — and it identifies any new polyps or cancers in the rest of your bowel (people who have had one bowel cancer have a slightly higher chance of developing another).
Your surveillance plan is tailored to your specific cancer — its stage, location, and the treatment you received. The schedule below is the typical pattern; your individual schedule will be confirmed at your post-treatment review.
Most patients follow a schedule along these lines:
- Clinic review + CEA blood test: every 3–6 months for the first 2 years, then 6-monthly for years 3–5.
- CT scan of chest, abdomen and pelvis: usually annually for 3–5 years.
- Surveillance colonoscopy: at year 1, then every 3–5 years depending on what is found.
If your cancer was higher-stage, you were younger at diagnosis, or your tumour had specific high-risk features, surveillance may be more intensive — for example, CT scans more often. Your specific plan will be discussed at your first post-treatment review, so you know what to expect.
Clinic review
A focused conversation about how you have been feeling, an examination, and a review of your blood tests and any imaging. The clinic review is often the most useful single check — a careful conversation about new symptoms is sensitive for early problems, and it is the time to ask any questions that have come up.
CEA blood test (carcinoembryonic antigen)
CEA is a protein made by some bowel cancers. After successful treatment, it drops; a rising trend on serial measurements can be an early sign of recurrence, sometimes before any imaging change. CEA on its own is not a diagnostic test — some things other than cancer can raise it (smoking, liver disease, inflammation), and some cancers do not make CEA at all. A rising trend prompts further investigation, not panic.
CT scan of chest, abdomen and pelvis
Imaging to check for any recurrence at the operation site or distant spread — most commonly to the liver or lungs. Annual CT for 3–5 years is the standard for stage II and III disease.
Surveillance colonoscopy
Checks the rest of your colon for new polyps or new cancers. The first surveillance colonoscopy is usually around 1 year after your surgery. The interval thereafter (3–5 years) depends on what is found — clean studies space out, polyps shorten the interval.
Surveillance is structured, but the schedule is not a replacement for telling us if something changes. Please contact our rooms between appointments if you develop any of:
- A new or persistent change in your bowel habits (looser, more frequent, or new constipation).
- Rectal bleeding or dark stools.
- Unexplained abdominal pain.
- Weight loss you have not been trying for.
- Persistent fatigue or symptoms of low iron.
- Any new lump or persistent swelling.
These symptoms do not usually mean recurrence — but they do warrant earlier review. Calling sooner rather than later is always welcome, and it usually brings reassurance.
Most patients return to standard population-level screening intervals after five years of clear surveillance. Surveillance colonoscopy usually continues at the interval recommended at your last review (typically every 3–5 years). Your GP usually takes over routine review at this point, and we remain available if anything changes.
The evidence is consistent: lifestyle factors meaningfully reduce the chance of recurrence and improve long-term survival after bowel cancer. None of these are guarantees — but they all help.
What helps
- Maintain a healthy weight and stay physically active — both reduce the risk of recurrence.
- Eat plenty of fibre, fruit, vegetables, wholegrains and legumes. Limit red and processed meat.
- Do not smoke. If you do, stopping reduces both recurrence and overall mortality.
- Limit alcohol — Australian guidelines suggest no more than 10 standard drinks per week.
- Encourage first-degree relatives (parents, siblings, children) to start screening earlier — see Family Screening for Bowel Cancer.
A rising CEA prompts further investigation — usually a CT scan, sometimes a PET-CT — to look for a source. One single elevated reading is not enough; the trend on serial measurements is what matters. A rising CEA does not automatically mean cancer is back — some causes are benign (smoking, liver inflammation) — so additional context is always needed before drawing any conclusions.
Yes — many patients describe a familiar wave of anxiety in the days before each scan or blood test. This is called "scanxiety" — and the people closest to you may feel it too. The reassuring reality is that the structured nature of surveillance means most appointments confirm everything is well. If you find the lead-up particularly hard, please tell us — we can sometimes adjust timing or the type of test in ways that help.
Most patients return to GP-led follow-up after five years of clear surveillance. Surveillance colonoscopy continues at the recommended interval, and you can be referred back to a colorectal surgeon if any new symptoms develop.
Yes — first-degree relatives (parents, siblings, children) of someone diagnosed with bowel cancer have a higher-than-average risk and should screen earlier and more frequently than the general population. See Family Screening for Bowel Cancer for the specific recommendations.
- Cancer Council Australia — Clinical practice guidelines for the prevention, early detection and management of colorectal cancer (NHMRC-endorsed)
- Australian Government Department of Health — National Bowel Cancer Screening Program
- Cancer Council Australia — Bowel cancer
- AIHW — National Bowel Cancer Screening Program: monitoring report
Need a specialist opinion?
If something in this article matches what you're experiencing, the most useful next step is a proper assessment. A GP referral is required.