Many diseases can cause hidden blood in the faeces. This is also known as Faecal Occult Blood (FOB), Human Occult Blood, or Human Hemoglobin. In the early stages, gastrointestinal problems such as cancer. ulcers, polyps, colitis, diverticulitis, and fissures may not show any visible symptoms, but only occult blood. Traditional guaiac-based methods lack sensitivity and specificity, and also have diet restrictions prior to testing. The FOB Rapid Test Cassette (Faeces) is a rapid test to qualitatively detect low levels of Fecal Occult Blood.