Black stool for 5 days suggests that the patient’s condition may be more dangerous. 1. 5 days of black stool suggests active gastrointestinal bleeding, which may be related to rupture of esophagogastric fundal varices, peptic ulcer, gastric cancer, etc. Large amount of bleeding may be accompanied by vomiting of blood, which is usually in the form of coffee, and some patients may also suffer from dizziness, fatigue, panic attacks, etc, and may even suffer from hemorrhagic shock. 2. At this time, we should actively treat the primary disease, and if necessary, we should also replenish fluids, blood transfusion and symptomatic support and other treatments. If the bleeding does not stop, endoscopic hemostasis should be chosen, such as argon gas hemostasis, metal clip hemostasis and other methods. If the patient has the above situation, he should immediately go to the regular hospital, after clarifying the cause of the disease, under the guidance of the doctor to carry out targeted treatment, in order to reduce the adverse effects of the disease.