Positive FIT Test: Bowel Cancer Screening

Clinical Scenario

David Hughes, 62, a semi-retired accountant, attends to discuss a letter from the GP surgery about his bowel screening results. His FIT (faecal immunochemical test) has come back positive with a result of 185 micrograms of haemoglobin per gram of faeces (positive threshold is 10). He received a brief letter asking him to book an appointment and has spent a week convinced he has bowel cancer. His mother died of bowel cancer aged 68. He is pale, anxious, and has barely slept since receiving the letter. He wants to know if he has cancer.

What This Case Tests

Explaining what a positive FIT test means without false reassurance or unnecessary alarm; contextualising the result — positive FIT does not mean cancer; understanding the bowel cancer screening pathway and two-week wait referral; managing the patient's fear in the context of his mother's death from bowel cancer; explaining the colonoscopy procedure and what to expect; providing emotional support while being honest about the diagnostic process

Common Mistakes Trainees Make

The three most common mistakes are: telling the patient not to worry because it is 'probably nothing,' which provides false reassurance and does not respect the significance of a positive FIT result — the level of 185 is significantly elevated and warrants urgent investigation; being so focused on the clinical pathway that you fail to address his emotional state — he has spent a week in terror thinking he has cancer; and not acknowledging his mother's death from bowel cancer as the specific fear driving his anxiety, which is the emotional context for the entire consultation.

The Consultation Challenge

David has spent a week in a state of fear. The letter was impersonal, the wait for the appointment felt endless, and his mother's death from bowel cancer is at the forefront of his mind. Before you discuss the FIT result, you need to address the emotional state he is in.

Start with acknowledgement: 'David, I can see this has been a very difficult week for you. Before we talk about the result, can you tell me what has been going through your mind since you got the letter?' This allows him to voice his fear — almost certainly that he has cancer like his mother. Validate it: 'Given what happened to your mum, it is completely understandable that this result has frightened you. I want to give you honest, clear information so you know exactly where you stand.'

Explain what a positive FIT test means: 'The test has detected blood in your stool sample. This is called a positive result, and it means we need to investigate further. But I want to be clear — a positive FIT test does not mean you have bowel cancer. Approximately 1 in 10 people with a positive FIT have cancer. The other 9 out of 10 have other explanations — polyps, haemorrhoids, inflammation, or sometimes no clear cause at all.'

Be honest about his result: the level of 185 is significantly above the threshold of 10, and higher levels are associated with a greater probability of significant pathology. Do not hide this: 'Your level is higher than the borderline, which means it is important that we investigate promptly. I am going to refer you urgently for a colonoscopy — this is the gold standard test that will tell us definitively what is causing the bleeding.'

Explain the colonoscopy: what it involves (a camera examination of the bowel under sedation), the bowel preparation (laxative the day before), how long it takes (30-45 minutes), and what happens after (results often available the same day, biopsy results within 2 weeks). Knowing what to expect reduces anxiety about the procedure.

Address his mother's history: 'Your mum's diagnosis does put you at a slightly higher risk, and that is one of the reasons the screening programme is so important — it catches things early when they are most treatable. Whatever we find, catching it now is far better than not knowing.'

Offer practical support: arrange the two-week wait referral today, give him a timeline for when to expect the appointment (within 2 weeks), and offer a follow-up appointment to discuss the results when they come through. Signpost to Bowel Cancer UK helpline if he needs support before the procedure.

Time check: Minutes 1-3 on acknowledging his emotional state and letting him express his fears. Minutes 3-6 on explaining the FIT result honestly with appropriate statistics. Minutes 6-9 on colonoscopy explanation and referral. Final 3 minutes on his mother's history, support resources, and follow-up.

How Examiners Mark This Case

Data Gathering and Diagnosis: Examiners assess whether you explain the FIT result accurately, contextualise the level (185 is significantly above threshold), and provide honest statistics about the probability of cancer versus benign causes. They look for whether you ask about symptoms — any change in bowel habit, rectal bleeding, weight loss, abdominal pain — and take a family history including the mother's bowel cancer diagnosis and age.

Clinical Management and Medical Complexity: Examiners evaluate whether you arrange an urgent two-week wait referral for colonoscopy, explain the procedure and preparation clearly, and provide a realistic timeline. Knowing the screening pathway and the role of FIT as a triage tool demonstrates system knowledge. Offering interim support and a follow-up appointment for results discussion shows continuity of care.

Relating to Others: This domain is paramount. Examiners look for emotional intelligence — recognising the patient's fear before launching into clinical information, acknowledging the mother's death as the specific anxiety driver, and being honest without either false reassurance or unnecessary alarm. The patient should leave understanding what the result means, what will happen next, and feeling supported through the process.

Example Opening

Strong opening: "Hello David, come in and sit down. I know you've had a difficult week since the letter. Before we go through the result, tell me — what has been going through your mind?"

When explaining the result: "The test has found blood in the sample, which means we need to investigate further. I want to be honest with you — I am not going to say 'don't worry, it's probably fine,' because I think you deserve straight information. What I can tell you is that about 9 out of 10 people with this result do not have cancer. But we need the colonoscopy to know for certain."

Avoid: "Try not to worry, it's probably just haemorrhoids" — this is dismissive, potentially inaccurate given the high FIT level, and undermines trust. He needs honesty, not false reassurance.

How This Appears in the SCA

Breaking bad news about screening results tests your ability to communicate uncertainty — the result is abnormal but the diagnosis is not yet known. Examiners value candidates who are honest without catastrophising, who address the emotional context, and who explain the investigation pathway clearly.

Key Statistic

Approximately 10% of patients with a positive FIT result are diagnosed with bowel cancer. The majority have benign causes including polyps, haemorrhoids, or diverticular disease. When bowel cancer is detected through screening, it is diagnosed at an earlier stage with significantly better survival rates.

Relevant Guidelines

• NICE NG12: Suspected cancer — recognition and referral (2-week wait pathway)
• NHS Bowel Cancer Screening Programme guidance
• NICE DG30: Quantitative faecal immunochemical testing
• BSG guidelines on colonoscopy.

Frequently Asked Questions

What does a positive FIT test result mean?

A positive FIT (faecal immunochemical test) means that haemoglobin — a component of blood — has been detected in the stool sample above the threshold level (10 micrograms per gram in the NHS screening programme). It does not mean cancer. Approximately 2% of people screened will have a positive result, and of those, about 10% will be diagnosed with bowel cancer. The remainder will have polyps (some of which are pre-cancerous and can be removed), haemorrhoids, diverticular disease, inflammatory bowel disease, or no identifiable cause. A higher numerical result is associated with a greater probability of significant pathology.

How should I explain colonoscopy to an anxious patient?

Use practical, demystifying language: 'A colonoscopy is a camera test that looks at the inside of your bowel. You will be given sedation so you are relaxed and comfortable — most people do not remember much about it. The day before, you take a preparation drink that clears the bowel. The procedure itself takes about 30-45 minutes. If they find anything like a polyp, they can often remove it during the same procedure. Results are usually discussed immediately afterwards, though biopsy results take about 2 weeks.' Addressing common fears — pain, embarrassment, and the preparation — reduces anxiety significantly.

How do I manage a patient whose parent died of bowel cancer?

Acknowledge the bereavement and its ongoing impact: 'Losing your mum to bowel cancer makes this result even more frightening, and I understand that.' Contextualise the family history: a first-degree relative with bowel cancer increases lifetime risk by approximately 2-3 fold, but it does not mean cancer is inevitable. Explain that screening exists precisely to catch problems early in people at higher risk. If the colonoscopy is normal, discuss whether enhanced surveillance is appropriate based on the family history (NICE recommends considering colonoscopic surveillance for first-degree relatives diagnosed under 50, or if multiple relatives are affected).

What is the difference between the NHS screening FIT and a symptomatic FIT?

The NHS Bowel Cancer Screening Programme sends FIT kits to all adults aged 56-74 (expanding to 50-74) every 2 years. The threshold for a positive result in the screening programme is 120 micrograms per gram. In symptomatic patients referred by GPs, the threshold used by many laboratories is lower — typically 10 micrograms per gram — because the pre-test probability of significant pathology is higher in a symptomatic population. David's result of 185 is above both thresholds and warrants urgent investigation regardless of the pathway.

What happens if the colonoscopy finds polyps?

Most polyps can be removed during the colonoscopy itself — a procedure called polypectomy. Polyps are sent for histological analysis to determine whether they are pre-cancerous (adenomatous) or benign (hyperplastic). If adenomatous polyps are found, the patient enters a surveillance programme with repeat colonoscopy at intervals determined by the number, size, and type of polyps. Removing adenomatous polyps prevents them from developing into cancer over time — this is one of the key benefits of the screening programme. Reassure the patient that polyp removal is straightforward and usually painless.