Can eating black licorice cause poop to be green?

Black stool: Eating black licorice is a known cause of black stools. Bile in stool causes green color. Blood in the upper GI tract acted on by digestive enzymes turns black and this is called melena or melenic stools. The stool will not only be black but "tarry" and sticky and very maladrous. Iron can turn the stool black but not foul smelling and tarry.