The normal stool color is yellow, if the color is not yellow color should consider some circumstances, such as the person’s diet that day will affect the stool color, and digestive function, if today ate very green vegetables or animal offal, there is a possibility that the stool color will turn black. If the digestion is not good there may be a brownish-green color change, or even some undigested food may appear. If the color of the stool is abnormal, black or asphalt, it may be considered a kind of gastrointestinal bleeding; if the color of the stool is not yellow stool and very nervous, or even accompanied by other symptoms, such as abdominal pain, diarrhea, dizziness, panic or a history of peptic ulcer, enteritis and other diseases, it is recommended that the patient immediately go to the hospital to see a doctor, the simplest is to do the routine stool plus OB test, stool occult blood The simplest way is to do a routine stool test plus OB test and fecal occult blood test, which can indicate whether the patient has possible gastrointestinal bleeding. If necessary, other tests such as colonoscopy may be done to further understand the cause and nature of the disease.