Occult Blood, Stool

Short Name: OCC
Sample required: Stool
Result Time: 2 HR

Fecal occult blood testing is performed on samples of stool in order to detect occult blood (blood that is not visible to the naked eye) in otherwise normal-colored stool. Fecal occult blood usually is a result of slow (often intermittent) bleeding from inside the upper or lower gastrointestinal tract. Occult bleeding has many of the same causes as other forms of more rapid gastrointestinal bleeding such as rectal bleeding (passage of red blood and/or blood clots rectally) and melena (black tarry stool as a result of bleeding from the upper intestines such as ulcers). This test can detect bleeding from almost anywhere in the digestive tract, and can come out POSITIVE for several conditions including colorectal cancer, esophagitis, gastritis, stomach cancer, ulcerative colitis and hemorrhoids. It can also be positive when aspirin or other medications that irritate the digestive tract have been used.