The difference between hematochezia and rectorrhagia is that rectal bleeding is not associated with defecation; instead, it is associated with expulsion of fresh bright red blood without stools.

In adolescents and young adults, inflammatory bowel disease, particularly ulcerative colitis, is a serious cause of hematochezia that must be considered and excluded.

However, as the blood from such a bleed is usually chemically modified by action of acid and enzymes, it presents more commonly as black "tarry" feces known as melena.

Eating beetroot can cause harmless red-colored feces (beeturia) because of insufficient metabolism of a red pigment, and is a differential sign that may be mistaken as hematochezia.

Consumption of dragon fruit (pitaya) or blackberries may also cause red or black discoloration of the stool and sometimes the urine (pseudohematuria).