Rectal bleeding can be caused by a range of conditions and diseases such as hemorrhoids, anal fissures, infections, and hard stool to name a few. Rectal bleeding often is indicated as bright red blood on toilet paper (usually after a bowel movement) or by the toilet bowl water becoming red. Rectal bleeding can also be present as extremely dark stool with a range in color from deep red/maroon to black, and sometimes appearing tar-like (melena).
Blood color can specify where the bleeding is coming from:
- Bright red blood usually points to bleeding low in the colon or rectum
- Dark red or maroon blood usually points to bleeding higher in the colon or the small bowel
- Melena usually means bleeding in the stomach
Not all rectal bleeding is visible to the eye. In some cases, rectal bleeding can only be seen by looking at a stool sample through a microscope.
Rectal bleeding common causes include:
- Anal fissure
- Chronic constipation
- Hard stools
Less common causes of rectal bleeding:
- Anal cancer
- Angiodysplasia (abnormalities in the blood vessels near the intestines)
- Colon cancer
- Colon polyps
- Crohn’s disease
- Ischemic colitis (colon inflammation caused by reduced blood flow)
- Proctitis (inflammation of the rectum)
- Ganglion cyst (colon inflammation caused by an infection)
- Radiation therapy
- Rectal prolapse (part of the rectum protrudes through the anus)
- Solitary rectal ulcer syndrome (a sore on the wall of the rectum)
- Ulcerative colitis
Schedule an appointment with us if you have rectal bleeding that lasts more than two days or earlier if the bleeding worries you. Usually people younger than 40 years old whose rectal bleeding is from an obvious cause, such as constipation, do not need testing. However, we recommend tests such as colonoscopy for people over 40 years old to rule out the possibility of colon cancer.