Dark or red stool
Signs of stomach bleeding vary depending on how much bleeding there is and how fast.
Stool may be loose and dark black, often called "tar-like", or may be more red, up to bright red for very brisk bleeding. Some people may also vomit red blood or brown, partly digested blood ("coffee grounds" vomit). Suspected blood in stool
or vomit should always be promptly evaluated as it can be very dangerous.