Fecal occult blood 3+ suggests gastrointestinal bleeding, such as acute gastritis, peptic ulcer, acute enteritis, ulcerative colitis, gastrointestinal tumors and other diseases. Consumption of animal blood products may also lead to abnormal fecal occult blood test, the details need to be combined with symptoms, medical history and other tests to clarify. 1. Disease causes: for example, acute gastritis is often triggered by drinking alcohol, taking non-steroidal anti-inflammatory drugs, etc., and there may be acid reflux, stomach pain and other symptoms; for example, peptic ulcer is often characterized by rhythmic gastroparesis (gastric ulcers are often associated with postprandial gastroparesis, and duodenal ulcers are often associated with fasting or nocturnal gastroparesis). For example, acute enteritis with history of unclean diet, diarrhea, abdominal pain and other symptoms; such as ulcerative colitis can have mucus, pus and blood stools; such as gastrointestinal tract tumors can also be lethargy, fatigue and other conditions. 2. Dietary reasons: mostly seen after consuming a lot of animal blood products, no other symptoms except black stool. For the case of 3+ occult blood in stool, it is recommended to consult a doctor to clarify the cause.