...,sore throat sometimes,nervousness ,stiff neck ,jaw,sore teeth ...was caused by a severe zinc deficency,that turned out to have ...docs suspect Pyroluria which causes zinc deficency etc etc.Long story short...
Bloody or tarry stools refer to a stool sample that is either dark red or black in color. Bloody or tarry stools can indicate bleeding or other injuries in your gastrointestinal tract. You may also have dark, discolored bowel movements after eating dark-colored foods.
Dark stool not associated with specific foods or medications can be more worrisome and may be an indicator of bleeding somewhere in the digestive system. The color and quality of the stool depends on where the bleeding is occurring and how fast the stool moves through the digestive system.