A fecal occult blood test (FOBT) may be issued in order to check for any conditions that could cause blood in your stool, such as anemia, a bleeding ulcer, polyps, inflammatory bowel disease, hemorrhoids, diverticulosis or cancer. A fecal occult blood test is conducted in three ways: the guaiac smear method, the over-the-counter flushable tissue method and the immunochemical method. Most blood in the bowel is intermittent, and not evenly distributed. In order to get a thorough sample, three different samples on three different days will usually be required to increase the chances of getting a stool with blood. A positive result for any condition will require follow-up testing, usually in the form of a sigmoidoscopy or colonoscopy, to check for any internal abnormalities.