Table of Contents
What is the purpose of guaiac test?
A test that checks for occult (hidden) blood in the stool. Small samples of stool are placed on special cards coated with a chemical substance called guaiac and sent to a doctor or laboratory for testing. A testing solution is put on the cards and the guaiac causes the stool sample to change color.
What is the purpose of a faecal occult blood test?
The fecal occult blood test (FOBT) is a lab test used to check stool samples for hidden (occult) blood. Occult blood in the stool may indicate colon cancer or polyps in the colon or rectum — though not all cancers or polyps bleed.
How accurate is a guaiac test?
The immunochemical and guaiac tests for significant colorectal neoplasia showed sensitivities of 61% versus 23.8%, specificities of 95.1% versus 97.7%, PPVs of 43.4% versus 39.0%, and NPVs of 97.5% versus 95.4%, respectively.
What type of specimen is needed for a guaiac test?
For a guaiac-based FOBT, you will need to collect 3 stool samples. Usually, these samples need to be collected in a clean container. This means that the sample is not mixed with urine or water from the toilet. Your test package will include an applicator.
What is a positive guaiac test?
For the FOBT, a positive test result indicates that abnormal bleeding is occurring somewhere in the digestive tract.
What is the positive result in guaiac test?
Heme, a component of hemoglobin found in blood, catalyzes this reaction, giving a result in about two seconds. Therefore, a positive test result is one where there is a quick and intense blue color change of the film.
What should you avoid before a stool test?
Watch what you eat. Two days before and the day of the fecal occult blood test, cut out all red meat, beets, broccoli, cantaloupe, carrots, cauliflower, cucumbers, grapefruit, horseradish, mushrooms, radishes, and turnips, which can all trigger false alarms.
What do I do if my occult blood test is positive?
If your test results are positive for blood, your health care provider will likely recommend additional testing, such as a colonoscopy, to figure out the exact location and cause of your bleeding. If you have questions about your results, talk to your health care provider.
What food can cause a false negative guaiac test?
Decreased gua- iac test sensitivity was associated with activated charcoal, di- methylamlnoethanol, red Chile, n-acetylcysteine, rifampin, red Jell-o (General Foods Corp, White Plains, NY), orange juice, Pepto-Bismol (Norwich Eaton Pharmaceuticals, Norwich, NY), slmethicone, spaghetti sauce, and several red wines.
Can I eat before a stool test?
What does a positive guaiac test look like?
How do you do a guaiac stool test?
How is this test done?
- Collect 1 of your stools in a dry container.
- Use a wooden applicator to put a small smear of stool (from the outside of the stool) on the card or slide you have been given.
- Seal the sample and write your name and date on it.
- Flush the unused stool down the toilet.
What do you need to know about the guaiac test?
Stool guaiac test. The stool guaiac test looks for hidden (occult) blood in a stool sample. It can find blood even if you cannot see it yourself. It is the most common type of fecal occult blood test (FOBT). Guaiac is a substance from a plant that is used to coat the FOBT test cards. Usually, you collect a small sample of stool at home.
What does a stool guaiac test look for?
The stool guaiac test looks for hidden (occult) blood in a stool sample. It can find blood even if you cannot see it yourself. It is the most common type of fecal occult blood test (FOBT). Guaiac is a substance from a plant that is used to coat the FOBT test cards.
What should I do if my guaiac test comes back positive?
If the stool guaiac results come back positive for blood in the stool, your doctor will likely order other tests, often including a colonoscopy. The stool guaiac test does not diagnose cancer.