In this Article

• What is rectal bleeding?
• Definition and description of rectal bleeding
• Origin of rectal bleeding
• Occult gastrointestinal bleeding
• What are the causes of rectal bleeding?
• Anal fissure
• Hemorrhoids
• Diverticulosis
• Colon cancer and polyps
• Polypectomy
• Angiodysplasias
• Colitis and proctitis
• Meckel's diverticulum
• Rare causes of rectal bleeding
• How is the cause and site of rectal bleeding determined?
• History and physical examination
• Anoscopy
• Flexible sigmoidoscopy
• Colonoscopy
• Radionuclide scans
• Visceral angiogram
• Blood tests
• How is rectal bleeding treated?
• Correcting low blood volume and anemia
• Determining the cause and site of bleeding
• Stopping bleeding and preventing rebleeding
• Rectal Bleeding At A Glance
• Rectal Bleeding Glossary
• Rectal Bleeding Index

What are the causes of rectal bleeding?

Many diseases and conditions can cause rectal bleeding. Common causes include anal fissures, hemorrhoids, cancers and polyps of the rectum and colon, diverticulosis, abnormal blood vessels (angiodysplasia), ulcerative colitis, ulcerative proctitis, Crohn's colitis, infectious colitis, ischemic colitis, and Meckel's diverticula.

Anal Fissure

An anal fissure is a fairly common, painful condition in which the lining of the anal canal is torn. An anal fissure is caused by constipation or a forceful bowel movement, though a tight anal muscle also may be a contributing factor. Once the skin is torn, each subsequent bowel movement can be painful, and the pain often is severe. The amount of bleeding that occurs with an anal fissure is small and usually is noticed in the toilet bowl or on the toilet paper as bright red in color. The symptoms of an anal fissure are commonly mistaken for hemorrhoids, but hemorrhoids generally do not cause pain with bowel movements. For more, please see the Anal Fissure article.

Hemorrhoids

Hemorrhoids are masses or clumps ("cushions") of tissue within the anal canal that contain blood vessels. Although most people think hemorrhoids are abnormal, they are present in everyone. It is only when the hemorrhoidal cushions enlarge that hemorrhoids can cause problems (such as bleeding or anal discomfort) and be considered abnormal or a disease. Like anal fissures, bleeding from hemorrhoids is usually mild and does not cause anemia or low blood pressure. Rarely, a person may develop an iron deficiency anemia as a result of repeated hemorrhoid bleeding over several months to years. For more, please see the Hemorrhoid article.

Rectal Bleeding - How Was Diagnosis Established

The MedicineNet physician editors ask:

How was the diagnosis of your rectal bleeding established?

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