Bloody diarrhea, also known as bloody stool or rectal bleeding, can be bright or dark red or tar-like. It can be a symptom ... This blood might also make your stool look darker than usual.

These include complications like ... stools, and bright red, maroon, or tarry stools. The stools may also be foul-smelling. Diverticulitis can be diagnosed with an abdominal CT scan and blood ...