Go to the emergency room or call 911 if you have
- A large amount of blood or clots
- Dizziness, fainting or a racing heartbeat
- Black, tarry stools or vomiting blood
- Significant bleeding while taking a blood thinner
What the color can tell you
- Bright red on the paper or in the bowl usually comes from near the end of the colon or the rectum. Hemorrhoids and small tears (fissures) are common causes, but polyps and cancer can look the same.
- Maroon or mixed into the stool suggests bleeding higher in the colon.
- Black and tarry usually means bleeding from the stomach or upper intestine, such as an ulcer. Iron pills and bismuth (Pepto-Bismol) can also turn stool black, without blood.
Make an appointment soon if
- You notice any new rectal bleeding, especially at 45 or older
- Bleeding comes with a change in bowel habits, belly pain, weight loss or fatigue
- A blood test shows iron-deficiency anemia
Don't assume it's hemorrhoids if you're young
Colon cancer is rising in adults under 50. A 2023 study in the Journal of the National Cancer Institute found that rectal bleeding and iron-deficiency anemia were among the earliest warning signs in younger adults, often months before diagnosis. Hemorrhoids are still the most likely cause, but bleeding that persists deserves an exam, and often a colonoscopy, at any age.
What an evaluation looks like
Usually an exam, a blood count, and depending on your age and symptoms, a colonoscopy. Many causes, from hemorrhoids to polyps, can be treated during the same visit or procedure. See also GI bleeding and anemia.
— Brian Frank, MD
Questions about bleeding? Call (813) 400-0543 or send a message.
Board-certified gastroenterologist (ABIM). Published October 8, 2026.
This page is general information, not medical advice. For a medical emergency, call 911.