Common GI Symptoms

Common GI Symptoms > What You Need to Know About Rectal Bleeding

What You Need to Know About Rectal Bleeding

What is rectal bleeding?
Rectal bleeding or bleeding from the anus is a common symptom. Rectal bleeding is often noted by the appearance of blood in the toilet bowl on passing motion, or on the toilet paper on wiping.

Whilst haemorrhoids (piles) are a common cause of rectal bleeding, the new onset of rectal bleeding in an individual who is >50, with associated symptoms and risk factors should warrant further evaluation to rule out cancer of the colon or rectum.

Causes of rectal bleeding

There are numerous causes of rectal bleeding:

  • Anorectal disease:
    • Haemorrhoids
    • Anal fissures
  • Diverticular disease
  • Inflammatory Bowel Disease
  • Colorectal Cancer

Less common causes of rectal bleeding:

  • Infective gastroenteritis
  • Coagulopathies (bleeding tendencies)
  • Ischemic colitis (inflammation of the colon caused by a decreased blood supply)
  • Trauma
  • Previous radiation therapy

What should I be worried about?

Passing sudden large amounts of blood from the rectum is a serious, life-threatening event. Sometimes the blood can be black and tarry and may indicate bleeding from high up in the digestive tract (possibly even in the stomach or small intestine).

If the volume of blood is large and you feel accompanying symptoms of feeling light-headedness, feeling faint, or chest pain, immediate medical attention is needed.

Smaller amounts of bleeding can also be worrisome and may be one of the symptoms of cancer of the colon or rectum. Other “red flags” associated with cancer of the lower GI tract include:

  • New onset of PR bleeding if you are > 50 years of age
  • Unexplained Loss of weight
  • A family history of cancer of the colon or rectum
  • Iron Deficiency Anemia (as detected by blood tests)
  • Change in bowel habit (especially recent onset constipation or going more frequently to the toilet)
  • A sensation of incomplete passage of stool or a lump in your back passage

What investigations are commonly done? 

Your doctor will take a detailed history followed by a physical examination. The doctor will probably perform an examination of your back passage. Whilst this can be potentially embarrassing and uncomfortable, it is an essential part of the examination.

Your doctor may proceed to other investigations:

  • Blood tests:
    • Full blood count
    • Ferritin and iron studies
    • Clotting studies if appropriate
  • Colonoscopy (see section on colonoscopy)
  • CT Colonoscopy (see section of CT colonoscopy)