Hi, please see a gastroenterologist. You may need a endoscopy to be done.

If you are not on any iron tablets then black stools denotes bleeding in the Upper GI tract. Visit a physician to confirm your diagnosis and appropriate treatment

Hello there..... Stool colour usually depends upon what kind of food you consume.... Add fiber to your diet increases the weight of your stool and speeds its passage through your intestines. Slowly begin to eat more fresh fruits and vegetables each day. Choose whole-grain breads and cereals..... Drink fluids. Drink plenty of water to keep the throat moist and prevent dehydration.....