A Stool Occult Blood Test is performed to determine the presence of microscopic blood in the feces. The appearance of blood in the stool may indicate polyps or colon cancer in the rectum or colon. Usually, occult blood is passed in small amounts that it can't be detected without using chemical substances.
Procedure of the Test:
Usually, three types of samples are collected by the laboratory technician to perform the test. There are two types of Stool occult blood testing: 1) Immunologic 2) Chemical
Chemical testing: In this, the lab technician uses a solution containing the chemical guaiac and an oxidizing chemical. If the presence of blood is diagnosed in the stool sample, the guaiac will turn blue after mixing it with the stool sample. It will turn blue because of the interaction takes place due to the presence of the oxidizing agent.
Immunologic testing: In this procedure, a sample of stool is mixed with the solution containing an antibody to the globin. The antibody is combined with a small amount of gold.
Why get tested?
The doctor may ask a patient to undergo the test to screen for colon cancer or to evaluate the possible causes of unexplained anemia. The doctor may ask to undergo the test if the patient experiences symptoms such as:
Changes in bowel habits
This test includes
Stool Occult blood
Following preparation are required before taking the test:
It is recommended to follow a special diet 48-72 hours before the test. Food items such as raw fruits, red meat, and vitamin C enriched foods or beverages should be avoided.
It is important to inform the doctor about the medications that are being taken by the patient.
Restrict the consumption of alcohol for at least 12-48 hours before taking the test.