Black stools in early pregnancy may be caused by the following factors.1. Food factors. Short-term use of too much black food, such as animal blood, animal liver, black rice, black beans, black fungus, spinach and so on, will appear black stool. Generally change the diet structure can be relieved, do not need special treatment. 2, drug factors. After taking iron, bismuth will appear black stool. It is a normal phenomenon after taking medication, and the stools will return to normal after stopping the medication.3. Disease factors. Black stools with abdominal pain, loose stools and other abnormal symptoms, to consider whether the upper gastrointestinal bleeding or a small amount of lower gastrointestinal bleeding caused by black stools. Need to go to the hospital for further consultation.