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 of Sjogrenâs syndrome are due to abnormal dryness of the affected glands and organs. Typical symptoms of Sjogrenâs syndrome include dry eye, dry cough, dry mouth, and poor oral and dental health. There are two types of Sjogrenâs syndrome, primary and secondary.