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).
Sjogren's syndrome is a common autoimmune disorder that attacks the mucus and moisture producing glands of the body, such as the glands that produce tears and saliva.In an autoimmune disorder, the body's immune system mistakes healthy tissues as foreign and potentially dangerous invaders into the body and attacks them.jogren's Syndrome: Sjogren's syndrome is an autoimmune disorder in which immune cells attack and destroy the glands that produce tears and saliva. Sjogren's syndrome is also ... more about Sjogren's Syndrome.