Blood in the stool can be bright red, maroon in color, black and tarry, or not visible to the naked eye. Rectal bleeding or blood in the stool should be evaluated by a healthcare professional.
Rectal bleeding also can be a symptom of other diseases or conditions such as:
- Anal fissures
- Colon polyps
- Ulcers (for example, ulcerative or Crohn's colitis)