Although it could simply be a dietary anomaly (what you eat), it is possibly internal bleeding from a specific spot in the large intestine, if it is consistent over time or recurring. Doctors are always on the look-out for 'blood in stools' problems for a few reasons. If it's consistent or recurring, one should definitely get it checked out soon.
Yellow
A dorsal Stripe is a dark brown/black stripe that goes straight down the back of a horse. Duns have them, But usually not paint duns.
Dark brown
Black stool is a condition where the feces are very dark and nearly black. Sometimes this is caused by supplements. Other times it is indicative of internal bleeding.
The food you ate.
Medication can alter the colour of stools
Black stool is a condition where the feces are very dark in color. It can be the symptom of a variety of diseases or disorders. To be absolutely sure, you should consult your local doctor who can make a diagnosis.
Shiny Golett and dark basculin(blue stripe)
No. faeces only glows if you put phosphorus in the faeces
Dark brown, the normal color.
dark almost black
Cyanide poisoning.