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Consultant Laparoscopic Colorectal and General Surgeon

Pre-surgery investigations

Rectal bleeding – what are the causes?

Treating bleeding in the digestive system

“Haemorrhoids are the most common cause of lower gastrointestinal bleeding. They can be managed effectively in the majority of patients with a combination of dietary changes, such as eating more fibre and simple outpatient procedures, such as injections or rubber banding. If these measures fail, surgery may be required.”

Mr Jonathan Wilson offers contemporary day-case haemorrhoidectomy, which is less painful than older techniques, but with the same end result. One of the techniques he favours is the haemorrhoidal artery ligation operation (eg. HALO).

Rectal bleeding can occur due to blood loss from either the upper intestine (oesophagus, stomach and duodenum) or from the lower digestive tract (small intestine, colon, rectum and anus).

Types of rectal bleeding

The most obvious type of rectal bleeding that occurs is fresh red blood coming from the bottom. This can be on the toilet paper or in the toilet, where it may be mixed with the stool or it may be separate. Although haemorrhoids (piles) are the most common cause, other conditions, benign and malignant, need to be considered.

Dark red, cherry coloured blood from the bottom may represent bleeding from further up in the large bowel. Black foul-smelling stools, known as melaena, ?often result from bleeding in the upper intestine.

Causes of upper digestive tract bleeding

  • Gastro-oesophageal reflux disease (GORD or GERD): when the oesophagus becomes inflamed because it is damaged by stomach acid, this can cause blood vessels to break down and bleed.
  • An ulcer in the stomach or duodenum: this can rupture, or just bleed steadily.
  • Oesophageal varices: large distended blood vessels that can cause a large bleed, and are usually associated with liver disease and cirrhosis.
  • Stomach or oesophageal cancer.

Causes of lower digestive tract bleeding

  • Haemorrhoids: fresh red blood is often noticed on the toilet paper or in the toilet. Lumps may also prolapse out from the anus.
  • Anal fissures (tears).
  • Diverticular disease.
  • Inflammatory bowel disease: Crohn’s disease or ulcerative colitis.
  • Bowel infection: blood and mucus may be visible in the diarrhoea.
  • Polyps in the large bowel.
  • Bowel cancer: the bleeding associated with colorectal cancer is usually occult (you can’t see it) and it can only be detected using a test.
  • Anal cancer.

Symptoms to look out for

Apart from obvious, bright red blood in the stools, other symptoms to look for include:

  • Darker blood in stools.
  • Stools that look like black tar.
  • Vomiting blood, either fresh red blood, or black coffee grounds.
  • Feeling very tired, lethargic, short of breath, and looking pale, which are all signs of anaemia.

Investigating rectal bleeding

After taking a detailed history of your symptoms, such as the frequency and description of your rectal bleeding, your doctor will probably organise some tests. Stool samples may be sent to the lab to look for infection or occult (invisible to the naked eye) blood, and you are likely to have some blood samples taken to test for anaemia (low blood count).

Diagnosing the source

Quickly identifying the source of rectal bleeding can prevent a medical emergency or identify a condition that needs urgent treatment. Most medical conditions are more easily treated when diagnosed early.

Depending on the outcome of these initial tests, you will probably then need an endoscopy. This may be an upper digestive tract examination (gastroscopy) or a colonoscopy, though sometimes both are required to pinpoint exactly where the problem lies.

In some cases, further radiological tests in the hospital may be required.

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