Name of the Procedure:

Blood, occult, by fecal hemoglobin determination by immunoassay, qualitative, feces, 1-3 simultaneous determinations. Common Name(s): Fecal Immunochemical Test (FIT), Occult Blood Test by Immunoassay

Summary

A Fecal Immunochemical Test (FIT) is a non-invasive test that detects hidden (occult) blood in the stool. It utilizes antibodies to identify the presence of hemoglobin from blood in feces. This test is qualitative, meaning it provides a positive or negative result rather than measuring the amount of blood present.

Purpose

The FIT helps to screen for gastrointestinal conditions that cause bleeding, such as colorectal cancer or large polyps. The goal is to identify potential sources of blood in the stool early, facilitating timely diagnosis and treatment to improve patient outcomes.

Indications

• Routine colorectal cancer screening, especially for individuals aged 50 and above.
• Unexplained anemia.
• Gastrointestinal symptoms such as unexplained weight loss, changes in bowel habits, or visible blood in the stool.

Preparation

• Avoid nonsteroidal anti-inflammatory drugs (NSAIDs) and aspirin for several days before the test, unless otherwise directed by a healthcare provider.
• Follow any specific dietary restrictions provided by the healthcare provider, though most FITs do not require changes in diet.
• Ensure proper collection of the stool sample according to the provided instructions.

Procedure Description

1. The patient is provided with a stool collection kit.
2. At home, the patient collects a small sample of stool using the provided tools.
3. The sample is applied to a test card or placed in a special container.
4. The sample is then sent to a laboratory where antibodies in the test react to the hemoglobin in the stool.
5. The laboratory performs up to three simultaneous determinations to ensure accuracy.
6. The results are qualitative, indicating whether occult blood is present or not.

Duration

The sample collection process takes around 10 minutes, and results are generally available within a few days after the laboratory receives the specimen.

Setting

The sample collection is done at home, while the analysis is conducted in a laboratory.

Personnel

Lab technicians and pathologists analyze the sample, and healthcare providers interpret the results and discuss them with the patient.

Risks and Complications

Rarely, false positives or false negatives can occur. False positives may necessitate further testing, while false negatives could delay diagnosis.

Benefits

• Non-invasive and easy to perform.
• Can detect early signs of colorectal cancer or other gastrointestinal conditions.
• Effective screening tool for individuals at average risk of colorectal cancer.

Recovery

No recovery period is necessary. Patients can resume normal activities immediately after sample collection.

Alternatives

• Colonoscopy: More invasive but provides direct visualization of the colon.
• Sigmoidoscopy: Less invasive but only examines part of the colon.
• Stool DNA Test: Detects genetic abnormalities linked to colorectal cancer, but more costly.
• Guaiac-based Fecal Occult Blood Test (gFOBT): Another non-invasive stool test, but less specific than FIT.

Patient Experience

The FIT procedure is straightforward and should not cause discomfort. Patients collect the stool sample in the privacy of their home and mail it to the lab. Follow-up with the healthcare provider is essential to discuss the results and any necessary next steps.