A fecal occult blood test (FOBT) is a medical test used to detect the presence of hidden (occult) blood in the stool. The test is typically done as part of a routine checkup to screen for colon cancer or other medical conditions that cause bleeding in the gastrointestinal tract.

During the test, a small sample of stool is collected and sent to a laboratory for analysis. The lab uses a special chemical to detect the presence of blood that is not visible to the naked eye. If blood is detected, further testing may be needed to determine the source of the bleeding.

The FOBT is a non-invasive test that can be done at home using a test kit provided by a healthcare provider. There are two types of FOBT: the guaiac FOBT and the fecal immunochemical test (FIT). The guaiac FOBT involves collecting a small sample of stool on a special card, which is then tested for the presence of blood using a chemical called guaiac. The FIT involves collecting a sample of stool and testing it for the presence of human hemoglobin, a protein found in blood.

A positive FOBT result does not necessarily mean that a person has colon cancer or another serious medical condition. Other factors, such as recent consumption of certain foods or medications, can cause false positive results. If a positive result is obtained, further testing may be needed to determine the source of the bleeding.

The American Cancer Society recommends that adults aged 45 and older receive regular colorectal cancer screening, which may include FOBT, colonoscopy, or other tests. The frequency of screening may vary depending on the individual’s age, family history, and other factors. A healthcare provider can recommend the most appropriate screening schedule based on the individual’s medical history and risk factors.