Eating dragon fruit for two days black stool may be normal, may also be due to the existence of digestive bleeding and other conditions. Dragon fruit, especially red dragon fruit is rich in iron and other trace elements, as well as anthocyanins, etc. can make the color of the stool become darker and darker, the appearance of nearly black, so out of the black stool is possible, this is normal, does not belong to the disease. If a patient with peptic ulcer eats dragon fruit after a peptic ulcer, intestinal tumors and other causes of gastrointestinal bleeding, can also lead to blood into the feces oxidation reaction, thus making the feces black. Can be identified through the fecal occult blood test, for positive means that there may be peptic ulcer bleeding led to black stools, for the pathological state. If you have eaten dragon fruit for two days and have black stools, you should consult a doctor and have a relevant examination.