After consuming a lot of mulberries, the stool will appear black, which is a normal physiological phenomenon. If this phenomenon persists after you stop taking mulberry, you should be alert to the possibility of gastrointestinal bleeding. 1. Physiological phenomenon: Mulberry contains a lot of melanin, after a large number of consumption, the pigment will be stained stool, resulting in black stool. This is a normal physiological phenomenon, no need to worry. After stopping the consumption of mulberry, this phenomenon can disappear in two or three days. 2. Pathological phenomenon: After stopping the consumption of mulberry, this phenomenon persists, or the patient is accompanied by other symptoms such as abdominal pain, should also be alert to the possibility of gastrointestinal bleeding, such as gastric bleeding, intestinal ulcer bleeding. If you can exclude the possibility of physiological phenomena, you should seek medical examination as soon as possible, and be targeted treatment.