If there's no obvious reason for a black stool (such as food, a supplement, or a medication like Pepto-bismol), it could be time to look for blood in the stool. 1  A variety of medical reasons can cause black stools that are also tarry with a foul smell.
1 Lungs, kidneys or liver. Inflammation may cause pneumonia, bronchitis or other problems in your lungs; may lead to problems with kidney function; and may cause hepatitis or cirrhosis in your liver.  Lymph nodes. A small percentage of people with Sjogren's syndrome develop cancer of the lymph nodes (lymphoma).
Symptoms are due to the damage of the moisture producing glands of the body and can affect the eyes, mouth, throat, nose, airways, skin, digestive system, and the vagina. In some people symptoms of Sjogren's syndrome can affect organs throughout the body, such as the lungs, kidneys, joints, blood vessels, and the nervous system.