Occult blood in stool may be a normal physiological phenomenon, or it may be the manifestation of certain diseases, such as peptic ulcer, drug factors, intestinal malignant tumor, intestinal inflammation, etc., and we should consult the doctor in time to find out the cause. 1. Physiological: related to diet, such as eating pig’s blood or animal caused by fecal occult blood, false-positive, stop eating this kind of food can return to normal, it is a normal physiological phenomenon, there is no abnormalities, you can not deal with. If the fecal occult blood test is conducted by immunization method, it can exclude the blood drinking caused by diet. 2. Peptic ulcer: when peptic ulcer bleeding, early bleeding is relatively small, the red blood cells in the blood are digested, decomposition, destruction, the naked eye can not see the bleeding feces, fecal occult blood positive. 3. Drug factors: taking cold and flu medicines such as indomethacin, etc., leading to gastric mucous membrane damage, occult blood. 4. Intestinal malignant tumor: mainly colon cancer and rectal cancer, early clinical manifestations are abdominal pain, occult blood in stool, diarrhea or constipation, anal falling and other symptoms. 5. Intestinal inflammation: there is inflammation in the intestinal tract, and the mucous membrane damage causes bleeding, and the fecal occult blood is positive. There are other possibilities for occult blood in stool, such as hemorrhoids, anal fissure, rectal bleeding, bacillary dysentery, colorectal polyps, etc. You should go to the gastroenterology clinic of the hospital in time to get a clear picture of the cause of the disease, and then follow the doctor’s instructions under the guidance of a professional physician.