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).
Research the causes of these diseases that are similar to, or related to, Sjogren's Syndrome: 1  One-sided swollen parotid salivary gland. 2  Both parotid salivary glands swollen. 3  Swollen cheeks. 4  Swollen jaw. 5  Dry mouth. 6  more related diseases...Â».