Usually black stool wipes can be yellow or black on the handkerchief. Because different reasons will have different performance. 1. is yellow: black stool usually due to eat some special food such as seaweed, as well as some special drugs such as iron-containing drugs, may make the stool appear black, not gastrointestinal bleeding, wiped on the handkerchief may be the color of the stool is yellow. 2. not yellow: due to some diseases, such as digestive system diseases such as peptic ulcer, stomach cancer, etc., upper gastrointestinal bleeding. The blood in the upper gastrointestinal tract turns black and is discharged from the body due to stomach acid, resulting in bloody stools. Stools are black and may appear dark red or reddish, not yellow, when wiped with hand towels. When black stools appear, you should pay attention to it and go to the hospital in time to have it clarified by stool routine and other tests.