A sudden change in stool color can be a cause for concern. While various factors can influence stool appearance, dietary intake is a common, and usually harmless, contributor. Understanding the potential impact of different foods on stool color can help alleviate anxiety associated with such changes.
Can Cherries Cause Dark Stool?
Consuming cherries can indeed result in dark or even black-appearing stool. This phenomenon is primarily attributed to anthocyanins, which are natural pigments responsible for the vibrant red and purple hues in cherries.
When cherries are consumed, these anthocyanin pigments pass through the digestive system. Unlike some nutrients, anthocyanins are not fully absorbed by the body. As they travel through the gastrointestinal tract, they retain their dark coloration, subsequently altering the color of the stool. This effect is temporary and considered a benign side effect of eating cherries.
When to Be Concerned About Dark Stool
While cherries can cause harmless dark stool, it is important to distinguish this from melena, which indicates bleeding in the upper gastrointestinal tract. Melena is characterized by stool that is typically jet black, tarry, and sticky. It also often has a distinctly foul, pungent odor. The dark color of melena results from the digestion of blood as it travels through the digestive system.
If dark stool is accompanied by other symptoms, medical attention should be sought promptly. These concerning symptoms can include abdominal pain, chest pain, nausea, vomiting (especially if it contains blood or looks like coffee grounds), dizziness, weakness, or lightheadedness. Persistent dark stool that is tarry or sticky, even without other symptoms, warrants evaluation by a healthcare provider to rule out internal bleeding.
Other Dietary Influences on Stool Color
Beyond cherries, other foods and supplements can temporarily alter stool color. Dark-colored fruits such as blueberries can lead to dark or even blackish stool due to their anthocyanin content. Consuming dark leafy greens, like spinach or kale, can result in green-tinged stool due to chlorophyll.
Certain medications and supplements are also known to cause temporary changes in stool color. Iron supplements commonly cause stool to appear dark green or black because of unabsorbed iron. Medications containing bismuth subsalicylate, used for upset stomachs and diarrhea, can also turn stool black. This occurs when bismuth combines with sulfur in the digestive tract to form bismuth sulfide, a black substance. These dietary and medicinal influences are generally harmless and resolve once the offending item is no longer consumed.