Rapid test to find hidden red blood cells in stool

Article written by Nguyen Thi Thuy Hang - Doctor of Microbiology - Laboratory Department - Vinmec Times City International General Hospital.

Blood in the stool is a sign of damage to the digestive tract including: tumors, polyps, bleeding, diverticular disease, colorectal cancer... Blood in the stool may not be visible. with the naked eye when the blood count is very small. That's why a fecal occult blood test helps detect this.

1. 2 methods of testing for hidden blood in stool

There are 2 main methods of testing for fecal occult blood used in the laboratory including:
Guaiac fecal occult blood test (gFOBT): This test requires the patient to take 2 -3 stool samples and must change diet, medication (stop anti-inflammatory drugs, non-steroidal anti-inflammatory drugs 7 days before sampling; avoid broccoli, radishes, red meat, vitamin C doses above 250mg/1 day in 3 days). Immunochemical FOBT or Faecal immunochemical tests (FIT): This test is more commonly used because of its advantages over gFOBT because of its higher sensitivity. It does not require any dietary restrictions prior to sample collection and can be performed on a random stool sample.

2. What is a fecal occult blood test?

Fecal occult blood test aims to detect very small amounts of blood in a stool sample that cannot be seen with the naked eye.
Blood in the stool indicates a lesion of the gastrointestinal tract. It can be caused by many causes, including: polyps, colitis, gastrointestinal bleeding, tumors, diverticular disease...
Blood in the stool can also be a sign of colorectal cancer Colorectal cancer (colorectal cancer is the 2nd leading cause of cancer death in the United States and the 3rd most common cancer in both men and women). Therefore, screening for fecal occult blood can help detect colorectal cancer early and effectively treat it.

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3. What is the purpose of finding hidden blood in the stool?

Screening for colorectal cancer . Diagnosis of conditions that cause gastrointestinal bleeding.

4. Who needs to be tested for hidden blood in the stool?

The American Cancer Society recommends colorectal cancer screening at ages 45-75. The American Association for Colorectal Cancer Action recommends starting screening at age 50 and earlier in high-risk populations.
Fecal occult blood tests should be performed annually.

5. What to do next when receiving fecal occult blood test results?

If the result is negative, no blood can be detected in the stool at the time of the test. However, that also does not mean that there is no colorectal cancer (in the case of non-bleeding tumors). Testers should perform a routine fecal occult blood test every year.
If the result is positive, it means there is damage somewhere in the digestive tract, but it does not mean colorectal cancer. The doctor needs to order some other tests, for example, colonoscopy to detect the bleeding site.

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6. Test for hidden red blood cells in stool at Vinmec Times City International Hospital

Currently, Vinmec Times City International General Hospital Vinmec Times City uses 2 types of tests to find hidden blood (also known as hidden red blood cells) in the stool. Both of these types are based on the immunoassay method.
Qualitative test (rapid test): only show whether or not occult blood in stool with threshold of 25 ng/dl. This test does not show how much hemoglobin a person has in the stool. If the test is positive, additional colonoscopy should be performed. Quantitative test (performed on OC-sensor pledia-Japan) : gives an estimate of human hemoglobin concentration in stool to give instructions for colonoscopy indication: hemoglobin 100-200 ng/ml: indication for colonoscopy. In this case, the specificity of the test for detecting lower gastrointestinal bleeding due to colorectal cancer was up to 97%. Hemoglobin <100 ng/dl: no indication for colonoscopy

Vinmec International General Hospital is one of the hospitals that not only ensures professional quality with a team of leading medical doctors, modern equipment and technology, but also stands out for its examination and consultation services. comprehensive and professional medical consultation and treatment; civilized, polite, safe and sterile medical examination and treatment space. Customers when choosing to perform tests here can be completely assured of the accuracy of test results.
Customers can directly go to Vinmec Health system nationwide to visit or contact the hotline here for support.

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Bài viết này được viết cho người đọc tại Sài Gòn, Hà Nội, Hồ Chí Minh, Phú Quốc, Nha Trang, Hạ Long, Hải Phòng, Đà Nẵng.