Stools that are generally tarry and oily and shiny are considered black stools and may be caused by upper gastrointestinal bleeding, medications, or diet.
Normal stool color is yellow or yellow-brown, if the stool is tarry and oily, then it is a black stool.
Black stool is mostly seen in upper gastrointestinal bleeding, such as erosive gastritis, gastric ulcer, duodenal ulcer, hemorrhagic necrotizing enterocolitis, etc. Because of the high location of the bleeding, the amount of bleeding is small, and it stays in the intestinal tract for a long time, and after oxidation, sulfur is formed, so black stool is discharged.
Taking bismuth, such as bismuth potassium citrate, etc., and iron, such as ferrous succinate, ferrous sulfate, etc., can all have black stools.
Eating certain foods, such as animal liver, animal blood products, black sesame seeds, black rice, etc. can cause black stools.
The causes of black stools are complex, so it is recommended to consult a doctor to find out the cause and follow the doctor’s instructions.