If black stool lasts more than a day or two and has an especially foul, tar-like smell, internal bleeding may be to blame. Common sources include peptic ulcers in the stomach or esophagus or inflammation from gastritis. In these cases, blood mixes with the stool as it travels through the digestive tract, causing the darker color. A doctor can confirm the presence of blood through a stool test and may recommend further investigation to determine the source.

This site offers information designed for educational purposes only. You should not rely on any information on this site as a substitute for professional medical advice, diagnosis, treatment, or as a substitute for, professional counseling care, advice, diagnosis, or treatment. If you have any concerns or questions about your health, you should always consult with a physician or other healthcare professional.