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

How is the cause and site of rectal bleeding determined?

Accurately diagnosing the location and the cause of rectal bleeding is important for directing treatment. Diagnosis with rectal bleeding relies on the history and physical examination, anoscopy, flexible sigmoidoscopy, colonoscopy, radionuclide scans, angiograms, and blood tests.

History and physical examination

The age of the patient may offer an important clue to the cause of rectal bleeding. For example, moderate to severe rectal bleeding in teenagers and young adults is more likely to come from a Meckel's diverticulum. Moderate or severe rectal bleeding among older individuals is more likely to be due to diverticulosis or angiodysplasias. Mild rectal bleeding in an adult with prior abdominal radiation treatment may be due to radiation proctitis.

The presence or absence of other symptoms also may provide important clues. Bleeding from diverticulosis, angiodysplasias, and Meckel's diverticula are usually not associated with abdominal or rectal pain. Rectal bleeding from ischemic colitis is often preceded by the sudden onset of lower abdominal, crampy pain. Fever, abdominal pain, and diarrhea often occur with colitis due to infection, ulcerative colitis, or Crohn's colitis. Mild bleeding accompanied by pain in the anal area during defecation (passing of stool) suggests bleeding from an anal fissure. A recent change in bowel habit such as increasing constipation or diarrhea suggests the possibility of cancer of the colon.

Inspection of the anus may disclose bleeding from a hemorrhoid or anal fissure. Unfortunately, most hemorrhoids and fissures are not actively bleeding by the time a patient arrives at the doctor's office. Thus, even if a doctor finds a hemorrhoid or anal fissure, he/she cannot be certain that they are the cause of the bleeding. Therefore, flexible sigmoidoscopy or colonoscopy will have to be done to exclude other potentially more serious causes of bleeding.

Rectal Bleeding - How Was Diagnosis Established

The MedicineNet physician editors ask:

How was the diagnosis of your rectal bleeding established?

Anonymously share your comment to help others.
Be the first to submit a comment

Submit Your Comment

Suggested Reading by Our Doctors

• Colonoscopy - Learn about the colonscopy procedure, what it is, why it is performed, preparation, complications, alternatives and the after effects of the screening exam on MedicineNet.com
• Abdominal Pain - Learn about abdominal pain (pain in the stomach / abdomen) including causes, symptoms, how abdominal pain is diagnosed, and how abdominal pain is treated.
• Fecal Occult Blood Test - Read about the fecal occult blood test in which there are two types, chemical and immunologic. Fecal occult blood tests are used to screen for colon cancer and colon polyps.

Read more Rectal Bleeding related articles »

Latest Medical News

• Gene Discovery Gives Clues to Crohn's Disease, Colitis
• Some IBD Drugs May Raise Skin Cancer Risk
• FDA OKs New Crohn's Disease Drug Cimzia