Faecal Immunochemical Test (FIT) | London Blood Tests

Screen for hidden blood in stool with our Faecal Immunochemical Test for £68. Home kit available, UKAS-accredited analysis, GP review optional.

The Faecal Immunochemical Test (FIT) is a non-invasive stool test used to detect hidden (occult) blood in the bowel, an early warning sign of colorectal cancer, polyps, and gastrointestinal disease. Testing is analysed in a UKAS-accredited laboratory, with clear results and an optional GP consultation.

What is a Faecal Immunochemical Test (FIT)?

The Faecal Immunochemical Test (FIT) detects tiny amounts of human haemoglobin in stool that are not visible to the naked eye. Unlike older faecal occult blood tests, FIT is highly specific to human blood and is not affected by diet or medications.

FIT is widely used in bowel cancer screening programmes and clinical practice to:

• Screen for colorectal cancer

• Detect pre-cancerous polyps

• Investigate unexplained bowel symptoms

• Triage patients who may need colonoscopy

Because bleeding from bowel lesions can be intermittent, FIT provides a sensitive method for early detection — often before symptoms become severe.

At London Blood Tests, FIT samples are processed using validated immunochemical methods aligned with UK gastrointestinal screening standards.

Benefits of the FIT Test

1. Early Detection of Bowel Cancer
   Identifies microscopic bleeding that may indicate early-stage colorectal cancer.

2. Non-Invasive and Painless
   No blood draw, no bowel prep, and no invasive procedures.

3. Highly Specific to Human Blood
   Unlike older stool tests, FIT does not give false positives from food.

4. Convenient Home Collection
   Sample is collected discreetly at home using a simple kit.

5. Supports Rapid Clinical Decisions
   Helps determine whether further investigation (e.g. colonoscopy) is required.

6. Useful for Symptomatic and Asymptomatic Patients
   Appropriate for screening and symptom investigation.

7. Optional GP Consultation
   Results can be reviewed with a GP to plan next steps if needed.

Why Do I Need a FIT Test?

You may benefit from a FIT test if you experience bowel symptoms or want preventive screening.

Common symptoms prompting FIT testing include:

• Changes in bowel habits

• Persistent diarrhoea or constipation

• Blood in stool (visible or suspected)

• Abdominal pain or bloating

• Unexplained weight loss

• Fatigue or iron deficiency anaemia

FIT is also recommended if you:

• Are over 45–50 years old

• Have a family history of bowel cancer

• Have iron deficiency without a clear cause

• Want reassurance without invasive testing

Because early bowel cancer can be asymptomatic, FIT plays a crucial role in early detection.

How the Test Works

At-Home Stool Collection (Primary Method)

1. Order Your FIT Kit

   • Order online or by phone.

   • The test kit is delivered discreetly to your address.

2. Collect Your Sample

   • Use the provided collection device to take a small stool sample.

   • No dietary restrictions or medication changes are required.

3. Secure Packaging

   • Seal the sample according to instructions using the prepaid packaging.

4. Return the Sample

   • Send the sample back to the laboratory using the provided method.

5. Laboratory Analysis

   • Sample analysed in a UKAS-accredited laboratory using immunochemical assays.

6. Results Delivery

   • Results typically available within 3–5 business days.

7. Optional GP Consultation

   • Discuss results and any further investigation with a GP.

Your FIT Test Results – Explained

FIT results are reported as positive or negative, often with a numerical haemoglobin concentration (µg Hb/g faeces).

General interpretation:

• Negative FIT: no significant blood detected

• Positive FIT: blood detected — further investigation recommended

Important notes:

• A positive FIT does not diagnose cancer, but signals the need for further tests

• A negative FIT does not completely exclude disease, especially if symptoms persist

• Results should be interpreted alongside symptoms and clinical history.