Black stools have a variety of causes. It can be caused by iron supplements as well as those who had ostomy surgery or colectomy. On the other hand, if the individual had GI bleeding in the past, has foul smelling stool or lasts for more than a few days, a doctor should be seen.
Food or supplements
Having black stools might be brought about by food, supplements, minerals or medications. The iron supplements that are used alone or as a component of a multivitamin given for iron-deficiency anemia can cause black stools.
Foods which are black, dark blue or green might also lead to black stools such as:
- Blueberries
- Black licorice
- Lead
- Iron supplements
In case the black stool is complemented by other signs such as feeling faint, pain, dizziness or vomiting, particularly if there is blood or appears as coffee grounds, a doctor must be seen right away. - Bismuth
Take note that a doctor must be consulted right away if the black stools could not be traced to a certain food, iron supplement or bismuth.
Black stools due to blood
Blood that originates in the upper part of the digestive tract such as the esophagus or stomach might turn the stool black or melena. Once the blood moves via the body and mingles with the enzymes that are part of the digestive process, the blood alters appearance from red to black.
In case the black stool is complemented by other signs such as feeling faint, pain, dizziness or vomiting, particularly if there is blood or appears as coffee grounds, a doctor must be seen right away.
A doctor must be seen about the possibility for bleeding and blood in the stool if any of these risk factors are present:
- Liver disease
- Peptic ulcers
- Esophagus tears
- Varices in the stomach or esophagus
- Intestinal ischemia
- Erosive esophagitis and gastritis