MODEL RELEASED. Stool blood test packaging and equipment being held by an elderly man. This is the Hemoccult II test, used to test human stools (faeces) for the presence of blood. It is a fecal occult blood test (FOBT) used to detect hidden (occult) blood and screen for the presence of colorectal cancer (CRC). Daily samples are collected with the spatula and placed on slides which are then sent off to a laboratory to be analysed. The original Hemoccult test, developed in 1970, is now marketed by Beckman Coulter.