Black poop can have various causes, ranging from harmless to serious. Some common reasons include:
- Eating dark-colored foods such as black licorice, blueberries, beets, or foods with dark dyes.
- Taking medications like iron supplements, bismuth-containing medicines (e.g., Pepto-Bismol), or activated charcoal.
- Internal bleeding in the upper gastrointestinal (GI) tract (esophagus, stomach, or first part of the small intestine), which causes the stool to turn black and tarry as blood is digested in the GI tract. This bleeding may result from ulcers, gastritis, esophagitis, tears from vomiting, swollen veins, or even cancer.
Black stools caused by bleeding often have a tarry texture and a distinctive foul smell, which helps differentiate from black stools caused by diet or medications. Because black stool may signal a serious medical condition, it is important to consult a doctor promptly if it persists or is accompanied by symptoms like stomach pain, vomiting, or weakness.
