Dark gray stools are not normal; normal stools are yellowish brown. Dark gray stools may be caused by eating a large amount of fat, cholestatic jaundice, taking barium sulfate and so on. 1. Eating a lot of fat: enteritis or insufficient secretion of pancreatic juice leads to poor digestion and absorption of fat, resulting in dark gray or grayish-white feces and frothy or greasy stools. 2. Cholestatic jaundice: cholestatic jaundice leads to bile not flowing into the duodenum, which can’t promote digestion, and the digestive function is reduced, so it is difficult to digest greasy food, and the stool will become gray. 3. Taking barium sulfate: barium sulfate, white loose fine powder, insoluble in water, acid-resistant, alkali-resistant, suitable for upper and lower gastrointestinal imaging, is not easy to be absorbed by the human body, and it is discharged from the digestive tract, mixing with the stool, which will make the stool turn gray. If the above symptoms occur, it is recommended to go to the hospital in time for early formal treatment.