Adults with green stools may be related to physiological reasons, indigestion, intestinal diseases and other factors. 1. Physiological reasons: if adults consume too much food containing chlorophyll, such as spinach, greens, etc., it may lead to dark green stool color. 2. Indigestion: If you don’t pay attention to your diet, often drink alcohol, eat spicy and stimulating food, etc., it will easily lead to the impairment of gastrointestinal function and the phenomenon of dark green stools. 3. Intestinal diseases: If you suffer from intestinal dysbiosis, short bowel syndrome and other diseases, it will lead to abnormal intestinal peristalsis, which will cause the bilirubin is not fully converted into bilirubin, and then discharged with the food residues, resulting in dark green stools. In these cases, you should go to the hospital immediately for consultation and standardized treatment after clarifying the cause of the disease under the guidance of a professional physician.