Usually folic acid stools will not turn black, and the black stools may be related to the iron supplements taken, consuming too much food containing iron, and bleeding from gastric ulcers. 1. Taking iron supplements: containing a large number of iron ions, when patients take, part of the iron ions will be digested and absorbed by the gastrointestinal tract, and part of the iron ions will be discharged with the feces, which will make the feces appear black. This is a normal phenomenon, and patients do not need to worry too much. 2. Consuming too much food containing iron: If the patient consumes too much food rich in iron during the period of taking folic acid, such as spinach, chicken blood, duck blood, etc., the patient will not be digested and absorbed by the gastrointestinal tract, and the iron ions will be discharged together with the feces. The iron that has not been digested and absorbed by the gastrointestinal tract will be excreted along with the feces, thus making the patient’s stools appear black. After stopping the consumption of these foods, the symptom of black stool can disappear on its own. 3. Gastric ulcer bleeding: If the patient has the primary disease of gastric ulcer during the period of taking folic acid, and the treatment is incomplete or improper, it may lead to the aggravation of the symptoms of gastric ulcer, and in serious cases, it may even lead to bleeding. After the blood is acted by the gastrointestinal tract, it will be discharged out of the body together with the feces, thus making the patient’s feces appear black. If the patient takes folic acid stools black, usually there are other reasons, because folic acid usually does not make the stools black, need to consider the above reasons or other reasons. If the stool is black, you need to go to the hospital in time to complete the relevant examination, to clarify the cause of the disease, and follow the doctor’s instructions for treatment.