Black stools after eating pig’s blood will usually return to normal after stopping eating pig’s blood for about 2~4 days. Pig’s blood contains more iron, if you eat too much pig’s blood at one time, the iron into the body after redox reaction will lead to black stool color, but in addition to the color change, the nature of the stool is normal, the body will not appear other uncomfortable symptoms, in the case of one bowel movement per day, the color of the stool can be restored in 2~4 days. If the color of stool never returns to normal after stopping eating pig’s blood and remains black, it may be caused by other reasons, such as upper gastrointestinal bleeding and other causes. If there are other discomforts or the black stools continue to be unrelieved, it should be taken seriously, and you should go to a regular hospital in time to get a clear diagnosis and adopt a suitable treatment plan under the guidance of the doctor to avoid delaying your condition.