It is normal to have black stools when eating iron-rich leafy vegetables, or during the application of iron or bismuth supplements. If this phenomenon also occurs when eating leafy vegetables with low iron content, or if the symptoms persist, the possibility of gastrointestinal bleeding should be considered. 1. Normal phenomenon: if you consume a lot of spinach and other iron-rich leafy vegetables, iron will react in the stomach and intestines, and then black stools will appear; during the consumption of leafy vegetables, when you also apply ferrous sulfate, bismuth pectin and other medicines, it can also lead to black stools. 2. Pathological phenomena: consumption of some leafy vegetables with low iron content, or the persistence of black stool symptoms, should also be alert to the possibility of gastric hemorrhage and other digestive disorders, at this time the patient should consult a doctor in a timely manner, active treatment. When the symptoms of eating leafy vegetables and black stools appear, it is recommended that patients go to the hospital in a timely manner to improve the relevant examinations, a clear diagnosis, and under the guidance of the doctor to choose the appropriate treatment and medication.