Take iron tablets to pull black stools, do not eat 2-3 days stool color will be restored. The iron content in iron medication is relatively high, and many people will have black stools due to the inability to fully absorb the iron content when taking iron supplements. This is mainly due to the oxidation reaction of iron with digestive juices in the digestive system and is oxidized to ferrous sulfate. The color of the stool will gradually return to normal after the drug is stopped. Since there is still some residual iron in the body, the darkening of the stool will continue for a period of time, usually about 2-3 days, and the color will gradually change to a dark yellow. Some people taking iron medication will be accompanied by constipation, these people will be because the feces in the intestinal tract for a relatively long time, so the color of the stool is black, the duration will be relatively long.