A positive fecal occult blood test generally indicates a case of gastrointestinal bleeding. When gastrointestinal bleeding is greater than 5 ml per day, the fecal occult blood will react positively. There are many diseases that cause positive fecal occult blood, such as peptic ulcer, gastric cancer, colon cancer, acute erosive bleeding gastritis, inflammatory bowel disease, etc. It should be noted that patients can also cause positive occult blood after consuming animal blood. Positive fecal occult blood only indicates the presence of gastrointestinal bleeding. To clarify the cause, further examinations, such as gastroscopy, colonoscopy, small intestine microscopy, abdominal ultrasound, tumor markers, abdominal CT, etc., are needed, and only when the cause is clear can the next step of treatment be carried out.