stool occult blood test
A stool occult blood test, also known as a fecal occult blood test (FOBT), is a diagnostic tool used to detect small amounts of blood in the stool that cannot be seen with the naked eye. This test is commonly used as a screening tool for colorectal cancer and other gastrointestinal conditions.
How it works:
- A stool sample is collected and sent to a laboratory.
- In the lab, a chemical reaction is used to detect the presence of hemoglobin (the protein in red blood cells) in the stool.
- If hemoglobin is present, it indicates that there is blood in the stool, which could be a sign of various conditions.
What it can detect:
- Colorectal cancer: Early detection of colorectal cancer is crucial for effective treatment.
- Polyps: Benign growths in the colon that can sometimes bleed.
- Hemorrhoids: Swollen veins in the rectum and anus that can bleed.
- Ulcers: Sores in the lining of the digestive tract.
- Diverticulosis: Pouch-like protrusions in the colon that can become inflamed and bleed.
- Other gastrointestinal conditions: Such as inflammatory bowel disease (IBD), infections, or blood vessel abnormalities.
When it's recommended:
Colon cancer screening:
Recommended for individuals at average risk for colorectal cancer, typically starting at age 45 or 50, and those at higher risk may be screened earlier.
Investigating symptoms:
If you have symptoms like abdominal pain, changes in bowel habits, or blood in the stool, your doctor may recommend a stool occult blood test.
Monitoring treatment:
The test may be used to monitor the effectiveness of treatment for certain conditions, such as polyps or inflammatory bowel disease.
Important note:
- A positive result (blood in the stool) does not automatically mean cancer. Further tests may be needed to determine the cause of the bleeding.
- There are different types of stool occult blood tests, including the guaiac-based FOBT (gFOBT) and the fecal immunochemical test (FIT). FIT is generally more sensitive than gFOBT.