This information is useful for children and adults
A woman in a blue short sleeved shirt visits with her doctor.
Why Yale Medicine?
  • Our doctors specialize in hard-to-treat gastrointestinal disorders.
  • The Yale Medicine Interventional Endoscopy program provides highly accurate diagnostic tests for the causes of rectal bleeding.
  • We have a world-renowned team of cancer specialists who treat colon cancer and related cancers.

Seeing blood in the toilet after you have had a bowel movement is more common than you might guess. There are multiple potential causes, ranging from from hemorrhoids to colon cancer. While rectal bleeding is more common in older patients, young people experience it as well. Regardless of age, it’s important to get it checked out promptly, says Hamita Sachar, MD, a Yale Medicine gastroenterologist and assistant professor of digestive diseases at Yale School of Medicine. “Rectal bleeding is an alarm symptom that might signal a more serious underlying condition. Don’t put off seeing a doctor for it.

Rectal bleeding usually appears as blood of varying colors (including bright red, maroon or black) in the stool. Rectal bleeding can be a symptom for a wide range of conditions, some more serious than others

Common causes of rectal bleeding include:

  • Hemorrhoids:  These are pillow-like blood vessels located inside and outside the rectum, that can become swollen and start bleeding. Common during pregnancy, after childbirth and in people who suffer constipation, hemorrhoids are frequently the culprit when young people experience rectal bleeding.
  • Bleeding lesions: Damage to the colon, rectum or anus, caused by infectious diarrhea, diverticulitis, or Crohn’s disease, can cause blood in the stool.
  • Anal fissures: A tear in the lower rectum, typically the result of passing a hard stool, can cause bleeding. This condition usually heals within a few weeks.

Less common—and more serious—causes include:

There are other possible causes for rectal bleeding as well. Proper diagnosis requires the expertise of a medical specialist.