Sixteen-month-old babies with black stools may be caused by eating black food, oral iron medication, intestinal bleeding disorders, etc., the specific need to consult a doctor for a clear diagnosis. 1. Eating black food: when taking some dark-colored food, the color of the stool will change with the color of the food, so when the baby eating black food such as black sesame, black rice porridge, etc. will appear to have black stool phenomenon, is a normal performance. 2. Oral iron-containing drugs: when the baby oral iron-containing drugs such as ferrous lactate oral solution, ferrous sulfate oral solution, due to the iron ions and intestinal flora will have a chemical reaction with the black color, so there will be the phenomenon of black stool. 3. Intestinal bleeding disorders: some intestinal bleeding disorders such as common gastritis, duodenal ulcer, etc. may make the baby black stool symptoms, but also may be accompanied by abdominal pain, vomiting, fever and other symptoms. When you find that your sixteen-month-old baby has black stools, you should consult a doctor promptly and actively cooperate with the doctor’s treatment.