My mate is bleedin black blood down below is that normal?

That depends: If your mate is a female- dark vaginal blood can be old blood that is being shed. If this is black, tarry malodorous bowel movements - that could be something that is called melena & is related to GI bleeding. If melena - that needs to be promptly medically evaluated. By the way "down below" is pretty non-specific. We are doctors on the site- you won't embarrass us by being more specific.