What does a positive guaiac test mean?
For the FOBT, a positive test result indicates that abnormal bleeding is occurring somewhere in the digestive tract.
What is another name for stool guaiac?
Blood in the stool may be a sign of colorectal cancer or other problems, such as polyps, ulcers, or hemorrhoids. Also called gFOBT, guaiac smear test, and stool guaiac test.
What is the principle of guaiac FOBT?
Test is based on the oxidation of phenolic compounds present in the guaiac to quinones resulting in production of the blue color. When a fecal specimen containing occult blood is applied to the test paper, contact is made between hemoglobin and the guaiac.
What does a positive faecal occult blood mean?
A positive fecal occult blood test means that blood has been found in the stool. Your doctor will have to determine the source of the bleeding, either by doing a colonoscopy or by doing an examination to determine if the bleeding is coming from the stomach or small intestine.
What color is a positive guaiac?
Background: In guaiac-based faecal occult blood tests (FOBT), blue colours are considered positive. Blue-green colours should also be considered positive. Distinct green colours are said to be due to bile and it is stated that these should be interpreted as negative.
What color change will denote positive test for blood?
[3] The blue color would signify a positive test result.
How is a stool guaiac done?
In brief: You collect a stool sample from 3 different bowel movements. For each bowel movement, you smear a small amount of the stool on a card provided in the kit. You mail the card to a laboratory for testing.
What does a positive guaiac test look like?
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.