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).
Knowledge center. Sjogren's syndrome (Sjoegrens SjÃ¶grens) syndrome is a chronic disorder of the immune-system a-long term autoimmune-disease in which the'patient s white blood cells attack the saliva and tear, glands leading to dry mouth and eyes because the'body s tear and saliva production is. reducedjogren's syndrome is an autoimmune disease-the patient's immune system attacks healthy cells and tissues, mistaking them for dangerous pathogens, such as infectious bacteria or viruses. Experts are not sure why Sjogren's syndrome affects some individuals, and not others.