Dark green stools may be caused by improper diet, gastrointestinal dysfunction or acute gastroenteritis, etc. It can be treated by adjusting diet, taking medicines to inhibit gastric acid and regulating gastrointestinal flora as prescribed by the doctor. 1. Improper diet: the patient may have eaten too much green food, the color pigment can not be absorbed by the human intestinal tract, and then there will be dark green stools. It is recommended that patients adjust their diet to reduce the intake of green food, this situation will improve. 2. Gastrointestinal dysfunction: Gastrointestinal dysfunction caused by gastrointestinal dynamics and secretion dysfunction, there will be the symptom of dark green stools, the patient can follow the doctor’s advice to choose to inhibit the gastric acid medication for treatment, such as famotidine, omeprazole and so on. 3. Acute gastroenteritis: after eating spicy, stimulating food, leading to the occurrence of acute gastroenteritis, sometimes there will be the symptom of dark green stool, patients can follow the doctor’s advice to choose to regulate the gastrointestinal flora of drugs for treatment, such as bifidobacteria triple live bacterial capsule and so on. When the patient has the symptom of dark green stool, it is recommended to go to the hospital in time for examination and diagnosis, and under the guidance of the doctor for treatment, do not take medication without authorization to avoid adverse symptoms.