What Does Solid Black Stool Mean?

If the black stool appears to be tarry, that is a sign of blood, which
is usually from a gastric bleed. Do you feel fatigued, dizzy ? If so you
should seek medical attention

I know of 3 different things it could be. 1) Blood in your stool and 2) You have taken some meds that you arent aware of and it's changing the color. And 3) Some type of Gastro problem