The Faecal Occult Test is also known as the stool test, faecal occult blood test, guaiac test, or hemoccult test. This test is used to detect hidden blood in the stool using a chemical reaction. The test is performed to diagnose gastrointestinal diseases such as colorectal cancer, ulcers, and inflammatory bowel disease. The stool test is important as early diagnosis can ensure effective treatment, which increases the chances of survival. The test is simple, non-invasive and quick. Synonyms for the faecal occult test show that it is referred to in different ways, but it serves the same purpose to detect blood in the stool to aid in the diagnosis of gastrointestinal diseases.