The green stool may be caused by the following reasons: 1. The green stool may be caused by consuming too many green vegetables containing chlorophyll. 2. The green stool may be caused by accumulated food or indigestion. 3. 4, in the consumption of cold drinks or seafood will appear diarrhea symptoms, then the stool will be green. 5, may be due to drug stimulation of the stomach and intestines, resulting in green stool. 6, patients eat too acidic food, will also appear such a situation. All of the above causes can cause green stools.