What Is a Positive FOBT Result and What Should I Do Next
General information only: This article provides general educational information about the FOBT screening programme and what a positive result means. It does not replace advice from your GP or specialist. If you have received a positive FOBT result, contact your GP promptly to arrange colonoscopy. Do not delay acting on a positive bowel cancer screening result. |
You Have Received a Positive FOBT — What Does It Mean?
If you have received a positive result from the National Bowel Cancer Screening Program’s faecal occult blood test (FOBT), it is natural to feel anxious. The first and most important thing to understand is this: a positive FOBT result does not mean you have bowel cancer.
A positive FOBT result means that trace amounts of blood have been detected in your stool sample — amounts too small to see with the naked eye. Blood in the stool can come from many different sources within the bowel, and the majority of positive FOBT results are caused by benign conditions. However, because bowel cancer and pre-cancerous polyps can also cause occult blood loss, a positive result requires follow-up investigation — specifically, colonoscopy — to identify the source.
Dr Devesh Kaushal performs colonoscopy at his Campbelltown consulting rooms for patients across South Western Sydney, including those referred following a positive National Bowel Cancer Screening Program result.
Positive FOBT ≠ Bowel Cancer A positive result means blood was detected in your stool sample. It does not diagnose bowel cancer. The next step is colonoscopy to find the source of the blood. Most positive FOBT results are caused by benign conditions — but the result must be followed up with colonoscopy. Do not ignore it. |
What Is the FOBT and How Does the National Bowel Cancer Screening Program Work?
The National Bowel Cancer Screening Program (NBCSP) is an Australian Government programme that provides free bowel cancer screening to eligible Australians aged 45 to 74. Participants are sent a home testing kit in the mail at regular intervals — currently every 2 years — and complete the test at home by collecting small samples from two consecutive bowel motions.
The test used is the immunochemical faecal occult blood test (iFOBT or FIT) — a highly sensitive test that detects human haemoglobin (blood protein) in the stool. Unlike older guaiac-based tests, the immunochemical test is specific for human blood and is not affected by red meat consumption or certain medications, reducing the rate of false-positive results.
What does a positive result mean in numbers?
Approximately 7 to 8% of people who complete the FOBT receive a positive result. Of those with a positive result who proceed to colonoscopy:
- Approximately 1 in 25 will be found to have colorectal cancer
- Approximately 1 in 4 will be found to have adenomatous polyps (pre-cancerous growths that can be removed at the time of colonoscopy)
- The majority will have a benign cause — such as haemorrhoids, diverticular disease, or no identifiable source
Why screening matters: Colorectal cancer is the second most common cancer in Australia. When detected at an early stage through screening — before symptoms develop — it is highly treatable. The FOBT programme exists to identify colorectal cancer and precancerous polyps early, when treatment is most effective. A positive result is the programme working as intended — it has detected something that requires further investigation. |
What Causes a Positive FOBT Result?
Many conditions can cause trace blood loss into the bowel that produces a positive FOBT. The test detects blood but cannot identify its source — that is the role of colonoscopy. Common causes include:
Cause | Notes |
Haemorrhoids (piles) | The most common benign cause. Haemorrhoidal bleeding is intermittent — a negative FOBT on one occasion does not exclude haemorrhoids as a future cause. |
Colorectal polyps | Adenomatous polyps are pre-cancerous growths that bleed intermittently. Removal at colonoscopy (polypectomy) prevents progression to cancer. A key reason for FOBT follow-up. |
Colorectal cancer | Bowel cancer can cause occult blood loss before any symptoms develop. Early detection through FOBT and subsequent colonoscopy significantly improves treatment outcomes. |
Diverticular disease | Small pouches in the colon wall can bleed — usually more heavily, but can cause trace occult bleeding. |
Anal fissure | A small tear in the anal canal can bleed with defecation. |
Inflammatory bowel disease | Crohn’s disease and ulcerative colitis cause bowel inflammation and bleeding. |
Angiodysplasia | Abnormal blood vessels in the bowel wall — more common in older adults. |
No identifiable source | A proportion of positive FOBT results have no identifiable cause found at colonoscopy — the bleeding source may have been transient or from the upper GI tract. |
What Happens Next — The Step-by-Step Pathway
1 | Contact your GP Call your GP after receiving a positive FOBT result. Do not wait — the recommended timeframe for colonoscopy after a positive FOBT result is within 30 days where possible. Bring the letter from the NBCSP to your GP appointment. |
2 | GP assessment Your GP reviews the result, takes a clinical history, and arranges a referral for colonoscopy. Your GP may also arrange blood tests including full blood count and iron studies — iron deficiency anaemia can indicate significant bowel blood loss. |
3 | GP referral for colonoscopy Your GP writes a referral to a specialist surgeon or gastroenterologist to perform the colonoscopy. Dr Kaushal performs colonoscopy at Campbelltown for patients referred with a positive FOBT result. |
4 | Book the colonoscopy Contact Dr Kaushal’s rooms on (02) 7906 8312 with your GP referral letter to arrange a colonoscopy appointment. Bring your Medicare card, referral letter and any recent blood test results. |
5 | Pre-colonoscopy preparation A bowel preparation is required before colonoscopy — a laxative solution taken the day before the procedure that clears the bowel to allow complete visualisation. Instructions are provided at booking. The procedure requires a half to full day — arrange a support person to drive you home. |
6 | Colonoscopy procedure Performed under sedation (you are not awake). The entire colon and rectum are visualised. Polyps are removed at the same time (polypectomy). Biopsies are taken of any suspicious areas. Results are available immediately for most findings; biopsy results take approximately 1 to 2 weeks. |
7 | Post-colonoscopy discussion Dr Kaushal discusses the findings with you at or following the procedure. If polyps were found and removed — no further action needed until the next surveillance colonoscopy. If cancer is found — a management plan is discussed and arranged. |
What Is a Colonoscopy? What to Expect
Colonoscopy is the definitive investigation for a positive FOBT result. It is a procedure in which a thin, flexible tube with a camera at its tip (colonoscope) is passed through the rectum to examine the entire large bowel (colon) — approximately 1.5 metres in length.
Key facts about colonoscopy:
- Sedation: Colonoscopy in Australia is performed under intravenous sedation — you are in a relaxed, sleep-like state and do not feel the procedure. You are not under general anaesthesia. Most patients have no recollection of the procedure.
- Duration: The procedure itself takes approximately 20 to 45 minutes. You will be in the day procedure unit for 2 to 3 hours including preparation, the procedure and recovery.
- Bowel preparation: The bowel must be empty and clean for the colonoscope to see the bowel wall clearly. A prescribed laxative solution is taken the day before the procedure. Following the preparation instructions carefully is essential — a poorly prepared bowel reduces the quality of the examination.
- Polypectomy: If polyps are found during colonoscopy, they are removed at the same time using a wire loop or biopsy forceps — a process called polypectomy. This removes pre-cancerous growths before they can progress to cancer.
- Biopsy: Tissue samples can be taken from any abnormal-looking area for pathological examination. Biopsy results typically take 5 to 10 working days.
- After the procedure: You will rest in recovery for approximately 30 to 60 minutes. You cannot drive for 24 hours after sedation — arrange a responsible adult to take you home. Most patients return to normal activities the following day.
Colonoscopy and Medicare: Colonoscopy following a positive FOBT result from the National Bowel Cancer Screening Program attracts a Medicare rebate. A valid GP referral is required. Contact Dr Kaushal’s rooms and your insurer to understand your expected out-of-pocket costs before the procedure. |
Do Not Delay — Why Acting Promptly Matters
A positive FOBT result should be acted on within 30 days wherever possible. Studies consistently show that delays in follow-up colonoscopy after a positive FOBT result are associated with worse outcomes — because any cancer that is present has additional time to grow and potentially spread.
Many patients delay because they feel well and assume the result must be a false alarm — particularly if they have no bowel symptoms. This is understandable but potentially harmful. The purpose of bowel cancer screening is to identify cancer before it causes symptoms. Waiting for symptoms to appear before acting on a positive result defeats the purpose of screening.
If you have received a positive FOBT result — act now: ✔ Call your GP this week ✔ Ask for a referral for colonoscopy ✔ Contact the rooms on (02) 7906 8312 to book your colonoscopy ✔ Aim for colonoscopy within 30 days of receiving the positive result If your GP has a long wait, contact Dr Kaushal’s rooms directly — the team can advise on current colonoscopy availability and urgency triage. |
After Colonoscopy — What Are the Possible Outcomes?
Colonoscopy Finding | What Happens Next |
Normal colonoscopy — no polyps or cancer found | Return to routine FOBT screening at 2-year intervals. The positive FOBT may have been from a transient or benign source that is no longer present. |
Hyperplastic polyps found and removed | Generally low-risk. Return to routine 2-year FOBT screening in most cases. |
Adenomatous polyps found and removed | Adenomas are pre-cancerous. Surveillance colonoscopy recommended — timing depends on the number, size and type of adenomas found. Your GP and Dr Kaushal discuss the appropriate surveillance interval. |
High-risk adenomas found | More frequent surveillance colonoscopy — typically in 3 years. Dr Kaushal discusses the specific follow-up plan based on the polyp findings. |
Colorectal cancer found | A multidisciplinary management plan is arranged — involving surgery, and where indicated, oncology assessment. Early-stage colorectal cancer is highly treatable. Dr Kaushal discusses the findings, staging requirements and management options at a dedicated consultation. |
Frequently Asked Questions
I feel completely well — do I really need a colonoscopy?
Yes. The entire purpose of the National Bowel Cancer Screening Program is to detect bowel cancer and pre-cancerous polyps before they cause symptoms — at a stage when they are most treatable. Early bowel cancer and adenomatous polyps typically cause no symptoms whatsoever. Feeling well does not reduce the importance of following up a positive FOBT result. A normal result on colonoscopy gives valuable reassurance; an abnormal result identifies something that can be treated before it becomes a more serious problem.
Could the positive result be from haemorrhoids?
Yes — haemorrhoids are the most common cause of a positive FOBT result. However, colonoscopy is still required even if haemorrhoids are the suspected cause. This is because colonoscopy is the only way to confirm that haemorrhoids are the source and to exclude coexisting colorectal polyps or cancer. Do not assume a positive result is from haemorrhoids without colonoscopy to confirm this.
I had a colonoscopy a few years ago — do I need another one?
A positive FOBT result always requires follow-up colonoscopy regardless of when you last had one. A colonoscopy performed previously cannot exclude changes that have occurred since. Contact your GP to discuss the timing of your previous colonoscopy and the appropriate management of your current positive FOBT result.
Is colonoscopy safe?
Colonoscopy is a well-established and generally safe procedure. Complications are uncommon but include perforation of the bowel wall (rare — approximately 1 in 1000 to 3000 procedures), bleeding after polypectomy (more common, usually minor and self-limiting), and reactions to sedation. Dr Kaushal discusses the risks and benefits of colonoscopy at the pre-procedure consultation, and specific consent is obtained before the procedure.
How do I book a colonoscopy with Dr Kaushal at Campbelltown?
Contact the rooms on (02) 7906 8312 with your GP referral letter and Medicare card details. The team will advise on current colonoscopy availability and book your appointment. Bring your GP referral letter, Medicare card and any recent blood test results to your appointment. A GP referral is required for a Medicare rebate on the colonoscopy procedure.
Specialist General Surgeon | Upper GI and Bariatric Surgery 4 Hyde Parade, Campbelltown NSW 2560 Phone: (02) 7906 8312 Email: [email protected] | drdeveshkaushal.com.au Office Hours: Monday – Friday, 9:00 AM – 5:00 PM Current hospital appointments and accreditations include: Sydney Southwest Private Hospital Liverpool | Campbelltown Public Hospital | Campbelltown Private Hospital | The George Hospital Medicare rebates and private health insurance benefits may apply depending on the service, referral and individual policy. Please contact the rooms and your insurer regarding fees and potential out-of-pocket costs. |
General information only: This article provides general information about the FOBT screening programme. A positive result requires follow-up colonoscopy — contact your GP promptly. Do not delay acting on a positive bowel cancer screening result.
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