4-5. DETERMINING PRESENCE OF OCCULT BLOOD IN STOOL
a. General. The presence of blood in body waste is abnormal. Blood in the stool may be bright red, which indicates that the blood is fresh and that the site of bleeding is in the lower gastrointestinal tract. On the other hand, black-tarry-feces means the presence of old blood and that the site of bleeding is higher in the gastrointestinal tract. When blood is present in the stool but cannot be seen without the use of a microscope, it is referred to as occult or hidden. A hemoccult test detects occult blood in feces.
b. Important Points.
(1) Do not confuse hemorrhoidal bleeding with upper gastrointestinal bleeding.
(2) Meat-free diet may be ordered 3 days before the test.