What Is A Faecal Occult Blood Test And Do I Need One?
faecal occult blood test singapore

Article first published on G&L Surgical

A Faecal Occult Blood Test (FOBT) is a name that may initially sound perplexing to many.

While most of us are familiar with various diagnostic and screening tests, the FOBT often doesn’t garner as much attention.

However, its role in preventive healthcare makes it a crucial test.

Let’s delve into what this test is and why it matters.

What Is Faecal Occult Blood Test?

The term “faecal occult blood” is pretty direct: ‘faecal’ relates to faeces, ‘occult’ means hidden, and ‘blood’ is self-explanatory.

Hence, a FOBT is a test to detect hidden blood in the faeces.

Blood in faeces can result from several medical conditions, some benign, like haemorrhoids, and others more serious, such as colon cancer. The blood is not always visible to the naked eye, thus the word ‘occult’. The FOBT is designed to catch these traces of blood even when they are not visibly apparent.

What Do The Results Mean?

A positive result from an FOBT does not necessarily mean one has a disease or condition but rather that traces of blood were found in the stool sample. This could be due to various reasons, such as dietary factors, medications, or benign conditions.

However, it can also be an early warning sign of more serious issues like colon polyps or colon cancer.

A negative result means no blood was detected in the stool sample. It’s a reassuring result, but it’s essential to understand that the test is not foolproof. There are instances where colon cancer or polyps might not bleed, and hence, the FOBT could come back negative.

Who Should Get A Faecal Occult Blood Test?

Who should get a faecal occult blood test, G&L Surgical, Dr Ganesh Ramalingam

The FOBT is typically recommended as a screening tool for individuals aged 50 and above, given that the risk of colon cancer increases with age. With that said, there are factors that you can use to evaluate if a Faecal Occult Blood Test should be considered:

Age Considerations

Statistics indicate that individuals aged 50 and older are at a heightened risk of developing colon cancer. As such, it’s commonly advised for people in this age bracket to consider regular screenings, including the FOBT, as part of their health check-up routine.

Family History

You might be more susceptible if colon cancer or polyps are in your family’s medical history. Individuals with a familial link are often encouraged to undergo this test earlier than the typical starting age of 50 and might need it more frequently.

Presenting Symptoms

Some symptoms shouldn’t be ignored. Persistent abdominal pain, unexplained weight loss, or noticeable changes in bowel habits might indicate an underlying issue. If you experience these symptoms, your doctor might recommend the FOBT as a preliminary screening tool.

Other Risk Factors

Prior Health Conditions: Individuals with certain health conditions, like inflammatory bowel disease (IBD), might be at an increased risk of colon cancer. In such cases, regular FOBT screenings could be beneficial.

Lifestyle Choices: Factors like a diet high in processed or red meats, smoking, or excessive alcohol consumption can elevate the risk of colon-related issues. If you identify with these lifestyle choices, regular screenings can be an effective preventive measure.

While the guidelines highlight specific groups who might benefit most from the FOBT, it’s essential to remember that individual health varies. Open discussions with your healthcare provider can give clarity on when and how often you should get screened. 

How To Prepare For A Faecal Occult Blood Test

faecal occult blood test preparation, G&L Surgical

Preparing for a Faecal Occult Blood Test (FOBT) is essential to ensure its accuracy. Here’s a simple guide to help you get ready:

Dietary Adjustments

  • Red Meat: It’s recommended to avoid or reduce your intake of red meat several days before the test. This is because it can sometimes produce a false positive result.
  • Certain Vegetables: Vegetables like broccoli, turnips, and horseradish might interfere with the test. It’s best to limit them for a few days leading up to your sample collection.
  • Vitamin C-rich foods: Consuming a large amount of vitamin C, whether from food sources like citrus fruits or supplements, can affect the test outcome. It’s advisable to keep this intake in check.


Some medications can influence the FOBT results. For instance, non-steroidal anti-inflammatory drugs (like ibuprofen) might cause minor bleeding in the digestive tract. If you’re on any medication, even if it’s over-the-counter, it’s crucial to inform your doctor. They can guide you on any necessary adjustments.

Avoid Potential Sources of Bleeding

  • Dental Procedures: If you have an upcoming dental procedure, schedule the FOBT before it to avoid detecting blood from your gums.
  • Anal Interventions: Avoid activities or procedures that might cause minor rectal bleeding, like certain types of exams or haemorrhoid treatment.

Collecting the Sample

Your doctor or nurse will provide you with a special kit to collect the stool sample. It’s essential to follow the instructions closely to ensure the sample is uncontaminated and valid for testing. Typically, you’ll be asked to take samples from more than one bowel movement.

Remember, the key to an accurate FOBT lies in the preparation. Proper preparation helps ensure that if blood is detected, it’s more likely linked to the conditions the test is designed to spot, rather than external factors or dietary influences. 

Importance Of Follow-Up Tests

FOBT Follow-up Colonoscopy, G&L Surgical

It’s paramount to understand that the FOBT is a screening tool, not a diagnostic one.

If the results come back positive, this does not confirm the presence of a disease. It merely indicates the presence of blood. In the event of a positive result, doctors usually recommend a colonoscopy to determine the cause of the bleeding.

A colonoscopy provides a detailed view of the colon and can help in detecting polyps, tumours, or other abnormalities

Colon cancer, when detected early, has a significantly higher chance of being treated successfully. This highlights the need for timely follow-up tests or consultations with a healthcare professional.


With early detection being the cornerstone of successful treatment in many diseases, especially cancer, one can appreciate the importance of a Faecal Occult Blood Test . Remember, as with any medical procedure or test, it’s always best to consult with your doctor about its relevance to your health.