Name of the Procedure:

Blood, occult, by peroxidase activity (e.g., guaiac), qualitative; other sources
Common Names: FOBT (Fecal Occult Blood Test), Guaiac Test

Summary

The fecal occult blood test (FOBT) is a non-invasive test used to detect hidden (occult) blood in the stool. This test uses a guaiac-based method to identify the presence of blood that is not visible to the naked eye, which can be an early sign of colorectal cancer or other digestive disorders.

Purpose

The FOBT is primarily used to screen for colorectal cancer. It can also help in diagnosing other conditions that cause gastrointestinal bleeding, such as ulcers, hemorrhoids, or inflammatory bowel disease. The goal of the procedure is to detect hidden blood in the stool early, which can lead to timely intervention and treatment.

Indications

• Routine colorectal cancer screening for individuals over the age of 50.
• Unexplained anemia or iron deficiency.
• Symptoms like persistent abdominal pain, changes in bowel habits, or blood in the stool.
• Family history of colorectal cancer or polyps.

Preparation

• Avoid certain foods (e.g., red meat, certain vegetables) and medications (e.g., aspirin, non-steroidal anti-inflammatory drugs) that can affect the test results for at least 48-72 hours prior to collecting samples.
• Follow specific dietary and medication guidelines as instructed by the healthcare provider.

Procedure Description

1. Collect stool samples: The patient will be provided with a kit to collect one or more small stool samples at home.
2. Apply the stool samples to the test cards: Using the provided applicators, smear thin layers of the stool samples onto the designated areas of the test cards.
3. Return the cards: Once the samples are collected and applied, they are returned to the healthcare provider or laboratory for analysis.
4. Laboratory analysis: The test cards are treated with a chemical solution. If the presence of occult blood is detected, the guaiac will react and change color, indicating a positive result.

Duration

The stool sample collection process takes a few minutes per sample. The overall time commitment, including multiple samples over a few days, might be around 3-7 days. Laboratory analysis can take a few days to a week.

Setting

The sample collection is performed by the patient at home. The analysis is conducted in a laboratory.

Personnel

• Patient: Collects the stool samples.
• Healthcare Providers: May include primary care physicians or gastroenterologists who interpret the results.
• Laboratory Technicians: Conduct the chemical analysis.

Risks and Complications

• False positives or false negatives due to dietary factors or medications.
• Rare tissue reaction or skin irritation from handling the test materials.

Benefits

• Early detection of colorectal cancer and other gastrointestinal issues, potentially before symptoms arise.
• Non-invasive and easy to perform, with no need for laboratory visits for sample collection.

Recovery

There is no recovery time required as this is a non-invasive procedure. Normal activities can be resumed immediately after sample collection.

Alternatives

• Colonoscopy: More invasive but provides a direct view of the colon and can also remove polyps.
• Sigmoidoscopy: Similar to colonoscopy but less extensive, examining only the lower part of the colon.
• Fecal Immunochemical Test (FIT): Another non-invasive stool test that does not require dietary restrictions.
• Stool DNA Test: Detects genetic mutations in stool samples linked to colorectal cancer.

Patient Experience

Patients might find the collection of stool samples slightly uncomfortable but generally easy to do. No pain is associated with the test itself. Proper instructions and materials are provided to ensure accuracy and ease of sample collection. Comfort measures include privacy and clear, concise instructions to reduce discomfort or apprehension.