What are Fecal Occult Blood (FOB) tests 2 and 3?

From the Guidelines

Fecal Occult Blood (FOB) tests 2 and 3 are not explicitly defined in the provided medical context, but based on the information given, it can be inferred that FOB tests refer to different methods of detecting blood in stool, such as the guaiac fecal occult blood test (gFOBT) and fecal immunochemical test (FIT). The provided evidence discusses stool-based tests for colorectal cancer screening, including high-sensitivity gFOBT and FIT, which detect blood in the stool using different methods 1. Some key points about these tests include:

• High-sensitivity gFOBT is based on chemical detection of blood
• FIT uses antibodies to detect blood
• Stool DNA tests detect DNA biomarkers for cancer in cells shed from the lining of the colon and rectum into stool
• Annual screening with FIT or sDNA-FIT provides an estimated greater life-years gained than annual high-sensitivity gFOBT or sDNA-FIT every 3 years 1. However, the terms FOB2 and FOB3 are not specifically mentioned in the provided evidence, and it is unclear what these terms would refer to in the context of Fecal Occult Blood tests. In real-life clinical medicine, the focus would be on using the most effective and accurate screening methods for colorectal cancer, such as FIT or sDNA-FIT, rather than on specific terminology that is not clearly defined in the medical context.

From the Research

Fecal Occult Blood (FOB) Tests

• Fecal Occult Blood (FOB) tests are used to detect hidden blood in the stool, which can be a sign of colorectal cancer or other gastrointestinal problems 2, 3, 4, 5, 6.

Types of FOB Tests

• There are several types of FOB tests, including: + Guaiac-based tests (e.g. Hemoccult) 3, 5 + Immunochemical tests (e.g. OC-Hemodia, Quick Chaser Occult Blood) 3, 4, 6 + Transferrin dipstick test (Tf) 4 ### Characteristics of FOB Tests
• The sensitivity and specificity of FOB tests can vary depending on the type of test and the population being screened 3, 4, 5, 6.
• Immunochemical tests tend to have higher sensitivity and specificity than guaiac-based tests 2, 3, 4.
• The transferrin dipstick test has been shown to have high sensitivity and specificity for detecting colorectal cancer and precancerous lesions 4.

Advantages and Disadvantages of FOB Tests

• Advantages of FOB tests include their simplicity, cost-effectiveness, and ability to detect hidden blood in the stool 2, 3, 5.
• Disadvantages of FOB tests include their potential for false-negative and false-positive results, as well as the need for repeated testing to confirm results 3, 5.