Colorectal cancer is one of the most common cancers affecting both men and women in Singapore. When it is caught early, treatment outcomes are generally more favourable.
Understanding the Faecal Immunochemical Test (FIT)
The faecal immunochemical test, commonly known as FIT, is a widely available colorectal screening option in Singapore. It requires no hospital visit, no preparation, and is generally well-tolerated.
What Is a Faecal Immunochemical Test (FIT)?
A faecal immunochemical test (FIT) is a non-invasive stool test that detects hidden blood in your stool, blood that is present in amounts too small to see with the naked eye. It is used as a first-line screening tool to identify people who may need further investigation for colorectal cancer or precancerous growths in the large intestine (the colon and rectum). The test is painless, done entirely at home, and requires no dietary changes beforehand.
FIT differs from older guaiac-based faecal occult blood tests (gFOBT) in an important way. The older test could be affected by certain foods eaten before the test, such as red meat or some vegetables, which sometimes produced misleading results. FIT uses antibodies (proteins that specifically recognise human blood) to detect blood in the stool, and does not require dietary restrictions. This makes FIT a widely used non-invasive stool screening method today.
How the Test Works
FIT works by detecting a protein called haemoglobin, which is found in red blood cells. When there is bleeding anywhere in the lower part of the digestive tract, such as from a polyp (a small growth on the bowel lining) or a tumour, tiny amounts of blood may pass into the stool. The FIT reagent in the collection kit reacts specifically to human haemoglobin, producing a result that is then analysed in a laboratory.
What FIT Can and Cannot Detect
FIT can detect blood associated with colorectal cancer and some larger precancerous polyps. However, it does not detect all polyps, particularly small ones that are not yet bleeding. A normal FIT result does not confirm that the bowel is completely clear. This is why regular, repeated testing at recommended intervals is important, and why some individuals may still need a colonoscopy (a camera examination of the large intestine) based on their individual risk profile.
Why Is Colorectal Cancer Screening Important in Singapore?
Colorectal cancer consistently ranks among the top cancers diagnosed in Singapore for both men and women. Early-stage colorectal cancer often causes no symptoms at all. People can feel entirely well while changes are developing in the bowel lining. By the time symptoms such as bleeding, pain, or a change in bowel habits appear, the disease may already be at a more advanced stage.
Screening allows doctors to detect problems before they cause symptoms, at a point when treatment options may be broader.
| Factor | Details |
|---|---|
| Cancer Ranking in Singapore | Among the most common cancers for both men and women |
| Age Group Most Commonly Affected | Adults aged 50 and above, though cases in younger adults are rising |
| Outcomes When Detected at an Early Stage | Generally more favourable; treatment options may be broader and outcomes are often more manageable |
| Outcomes When Detected at a Late Stage | Treatment is more complex and outcomes may be less predictable |
| Recommended Screening Start Age | 50 for average-risk individuals; earlier for those with risk factors |
The Link Between Early Detection and Outcomes
When colorectal cancer is found at an early stage, it is often confined to the inner lining of the bowel. Surgical and other treatment options may be less extensive, and outcomes are generally more favourable. When cancer is found at a later stage, it may have spread to nearby lymph nodes or other organs, requiring more extensive treatment.
Who Should Get a FIT in Singapore?
FIT is recommended primarily for average-risk adults who have no significant personal or family history of colorectal cancer. It is a practical option for people who are due for routine screening and wish to start with a non-invasive approach.
Age-Based Screening Recommendations
Singapore’s national Screen for Life programme recommends that average-risk adults begin colorectal cancer screening from the age of 50. FIT is one of the recommended options within this programme, and subsidies are available for eligible Singapore citizens and permanent residents at Community Health Assist Scheme (CHAS) GP clinics and polyclinics.
Certain international guidelines, including those from the United States, recommend starting colorectal cancer screening from age 45 for average-risk adults. In Singapore, the national programme currently begins at age 50. If you are between 45 and 49 and have concerns about your risk, speaking with your doctor can help determine whether earlier screening is appropriate in your individual situation.
Risk Factors That May Warrant Earlier or More Frequent Screening
- A first-degree relative (parent, sibling, or child) who has been diagnosed with colorectal cancer or colorectal polyps
- A personal history of colorectal polyps or inflammatory bowel disease (such as Crohn’s disease or ulcerative colitis, both of which cause long-term inflammation of the bowel)
- A known genetic condition such as familial adenomatous polyposis (FAP) or Lynch syndrome, which may raise colorectal cancer risk
- A previous diagnosis of colorectal cancer, even if successfully treated
If any of these apply to you, you may wish to discuss a more tailored screening plan with a specialist rather than relying on standard age-based recommendations.
When a Colonoscopy May Be Recommended Instead of FIT
FIT is suitable for average-risk individuals. If you fall into a higher-risk category, your doctor may recommend a colonoscopy as a more thorough first-line investigation. A colonoscopy allows the doctor to directly inspect the entire lining of the large intestine using a thin, flexible camera, and to remove any polyps found during the same procedure. It provides more detailed information than FIT alone, which is why it may be preferred for people with elevated risk.
How to Do a FIT: A Step-by-Step Guide
The process is straightforward, takes only a few minutes, and requires no bowel preparation (such as the laxatives required before a colonoscopy) and no dietary restrictions.
Preparing for the Test
Before you collect your sample, read the instructions that come with your FIT kit carefully, as different brands may have slightly different steps. Check the expiry date on the collection tube and keep the kit at room temperature, away from direct sunlight, until you are ready to use it.
Collecting and Submitting Your Sample
- Use the toilet as you normally would.
- Using the small brush or collection tool in the kit, collect a small sample of stool by brushing the surface in several places.
- Insert the brush back into the collection tube, seal it securely, and label it with your name and date of collection.
- Return the sample to your clinic, polyclinic, or the designated laboratory as soon as possible, ideally within the timeframe specified in your kit instructions (usually within 24 hours, or as directed).
Quick Tips for a Smooth FIT Experience
- Collect your sample first thing in the morning when it is freshest.
- Do not collect a sample during your menstrual period, as this can affect the result.
- If you have visible bleeding from haemorrhoids on the day of collection, it may be worth waiting until the bleeding has settled before collecting your sample, or speaking with your doctor about the best timing.
- Return your sample promptly, as delays can affect accuracy.
- Contact your clinic if you are unsure about any step.
What Do FIT Results Mean?
Negative (Normal) Result
A negative FIT result means that no hidden blood was detected in your stool sample. However, it does not mean that screening is complete. A negative result reflects only the sample provided on that day. Bowel changes can develop at any time, which is why repeating the FIT annually (or at whatever interval your doctor recommends) remains important even after a normal result.
Positive (Abnormal) Result
A positive FIT result means that hidden blood was detected in your stool. A positive result does not mean you have cancer. It means that something in the bowel may be causing a small amount of bleeding, and this needs to be investigated further. The standard next step after a positive FIT is a colonoscopy, which allows a doctor to examine the bowel directly and identify the source of the bleeding.
Arranging this follow-up promptly is advisable. In most cases, the cause turns out to be something benign (non-cancerous).
Common Causes of a Positive FIT Besides Cancer
- Haemorrhoids (piles), which are swollen veins around the anus or lower rectum
- Anal fissures (small tears in the skin around the anus)
- Benign polyps (non-cancerous growths on the bowel lining)
- Inflammatory bowel conditions
- Minor irritation or injury along the digestive tract
A colonoscopy can help determine the exact cause so that appropriate management can be arranged.
How Accurate Is FIT Compared to Other Screening Methods?
FIT is a practical non-invasive screening tool for average-risk individuals and can help identify cases of colorectal cancer, though its sensitivity for detecting precancerous polyps, particularly smaller ones, is more limited.
| Screening Method | How It Works | What It Detects | Frequency | Invasiveness | Best Suited For |
|---|---|---|---|---|---|
| FIT (Faecal Immunochemical Test) | Detects hidden blood in stool using antibodies | Colorectal cancer; some larger polyps | Annually | Non-invasive; done at home | Average-risk adults as a first-line screen |
| Colonoscopy | Camera examination of the entire large intestine | Cancer and polyps of all sizes; allows removal during procedure | Every 10 years (if normal) | Invasive; requires bowel preparation and sedation | Higher-risk individuals; follow-up after positive FIT |
| Stool DNA Test | Detects abnormal DNA and blood in stool | Cancer and some precancerous polyps | Every 1–3 years | Non-invasive; done at home | Not currently available as a standard option in Singapore; may be accessible privately or in other countries |
Taking Charge of Your Colorectal Health
FIT offers a low-barrier entry point into regular screening. It is easy to do, fits into your routine at home, and provides useful information about your bowel health. If the result is normal, it is reassuring. If it is positive, it provides an opportunity to investigate and act at an earlier stage.
Your age, family history, and lifestyle all play a role in determining the most appropriate screening approach for you. Speaking with a doctor about your individual circumstances is a helpful way to build a screening plan that provides useful information at the right intervals.
When to Seek Professional Help
- Visible blood in your stool or on the toilet paper
- A persistent change in your bowel habits, such as ongoing diarrhoea, constipation, or a change in stool shape
- Unexplained weight loss
- Persistent abdominal discomfort, bloating, or cramping
- A feeling that your bowel does not empty completely
These symptoms do not necessarily indicate cancer, but they do warrant timely assessment. A positive FIT result also warrants prompt follow-up with a specialist, even if you feel completely well.
Commonly Asked Questions
Is FIT the same as a colonoscopy?
No. FIT is a non-invasive stool test done at home that looks for hidden blood in your stool. A colonoscopy is a procedure performed by a doctor, in which a thin, flexible camera is used to visually examine the entire lining of the large intestine. FIT is a screening tool; a colonoscopy provides a direct, detailed view of the bowel and can also remove polyps during the same procedure.
How often should I repeat a FIT?
For average-risk adults, FIT is generally recommended once a year. Annual testing helps account for the fact that bowel changes can develop at any time, and that FIT reflects only the sample collected on a given day. Your doctor may recommend a different interval based on your personal risk factors or previous results.
Can I do a FIT if I have haemorrhoids?
Yes, but with some care. Haemorrhoids (piles) can sometimes cause bleeding that shows up on a FIT, potentially producing a positive result that is not related to cancer. If you have active bleeding from haemorrhoids on the day you plan to collect your sample, it may be worth waiting a few days until the bleeding has settled before collecting. If you are unsure, speaking with your doctor about the best timing is advisable.
Where can I get a FIT done in Singapore?
FIT is available at polyclinics, CHAS-accredited GP clinics, and private medical practices across Singapore. Eligible Singapore citizens and permanent residents may access subsidised FIT testing through the Screen for Life national screening programme. Private colorectal and general surgery clinics, including specialist practices, can also arrange FIT testing and guide you through the follow-up process.
Does a normal FIT result mean I definitely do not have colorectal cancer?
A negative FIT result is reassuring and means no hidden blood was detected in that particular sample. However, FIT does not detect all polyps, and a cancer that is not bleeding at the time of testing may not be identified. This is why repeating the test at recommended intervals is important, and why individuals with risk factors or symptoms may wish to discuss whether additional investigation, such as a colonoscopy, is appropriate.
Next Steps
If you are aged 50 or above and have not yet started colorectal cancer screening, you may wish to check whether you are eligible for subsidised screening under Singapore’s Screen for Life programme, and ask your GP or a colorectal specialist about arranging a FIT.
If you have already had a FIT and received a positive result, arranging a follow-up colonoscopy promptly is advisable. In most cases, the cause is benign, but prompt investigation provides a clearer picture and more options.
If you have a family history of colorectal cancer, known risk factors, or symptoms that concern you, speaking with a colorectal specialist may be a helpful next step. They can help you determine whether FIT is the right starting point or whether a more thorough investigation is warranted from the outset.
Speak with a Colorectal Specialist About Your Screening Options
If you are unsure whether FIT or a colonoscopy is the right choice for your situation, speaking with a colorectal specialist in Singapore may help. A consultation can help clarify your risk profile, explain your options in plain terms, and support you in putting a clear, personalised screening plan in place.
