Have been vomiting and some of it has been black also had some diarrhea which also has been black?

See gastroenterologi: You may have GI bleed , needs to be seen by gastroenterologist. Mostly you have upper GI bleed causing blood in vomiting and subsequent causing black stool which is blood from stomach goes in intestine and become black. See doctor.

C MD NOW: Unless you are taking pepto bismol (bismuth subsalicylate) (and maybe if you are), black stools can be from bleeding from the gut, likewise vomiting black material. Could be a serious problem, loss of at least a half cup of blood. Iron pills can also give black stools but see doc now.