There are many causes to rectal bleeding. Read on to understand what you must do should you encounter this problem.

Rectal bleeding or hematochezia, refers to the passage of fresh red blood through the anus or back passage. The colour of the blood would suggest that bleeding is arising from the distal colon or rectum, which forms the tail end of the large intestine. While bleeding from the rectum or anus may be alarming, most causes are treatable. It is not advisable to delay medical attention as rectal bleeding may be the initial symptom of a serious bowel condition. Moreover, the chronic loss of blood may lead to severe anaemia which can be life- threatening.

What causes rectal bleeding?

There are a multitude of conditions that lead to rectal bleeding. These include:

  • Haemorrhoids or piles: a common cause of rectal bleeding, haemorrhoids are swollen veins within the anus. The causes of haemorrhoids include chronic constipation, straining during bowel movements, pregnancy etc. Aside from being a common cause of rectal bleeding, haemorrhoids can also cause significant pain.
  • Anal fissure: this refers to a split or tear in the skin and mucosa around the anus. When this happens, the pain is usually greater than the amount of bleeding. Blood is often noted coating the stools or on wiping. The treatment of anal fissures is usually office-based and rarely involve surgery
  • Colitis or proctitis: inflammation of inner lining of the colon or rectum can lead to significant fresh bleeding. The causes are varied and include bowel infection, bowel ischaemia, vasculitis or after radiation therapy.
  • Inflammatory bowel disease (IBD): people with an IBD may experience rectal bleeding but this is often accompanied by other symptoms of sever abdominal pain, bloody diarrhoea, weight loss and fever
  • Polyps: this refers to a growth within the large intestine or rectum. Large polyps can be a cause of bleeding or mucus secretion. These have a high risk of cancer. Depending on the type, even smaller polyps may turn cancerous if left untreated
  • Colon or rectal cancer: bleeding is often one of the first or only symptom of cancer in the colon and rectum. Blood vessels on the surface of the cancer are fragile and bleed easily with the passage of stools. This is the reason colonoscopy is such as important investigation when rectal bleeding occurs.

Will rectal bleeding go away on its own?

The duration of rectal bleeding depends on the underlying condition and its severity. It is advisable to consult your doctor as soon as possible to determine the cause and get the correct treatment. At Thomas Ho Surgery, our specialists will provide the thoroughness and expediency of care to determine the cause and advise treatment.

Can rectal bleeding lead to serious consequences?

Intermittent episodes of mild rectal bleeding arising from haemorrhoids are often ignored by patients. Conversely, continuous mild bleeding may lead to severe anaemia while severe large volume bleeding may lead to hypotension or dangerously low blood pressure. Delay in treatment could lead to eventual organ damage such as the heart, brain, and kidneys. As such, you should seek immediate medical attention if the following additional symptoms are present:

  • Chest pain or discomfort
  • Shortness of breath
  • Blurred vision
  • Dizziness
  • Clammy and cold skin


Undiagnosed large polyps may also progress to colon cancer. Most colorectal cancers do not exhibit visible symptoms in the early stages, so it is important to detect this as early as possible to prevent the spread of cancer.

How to identify symptoms of rectal bleeding?

The clearest evidence of rectal bleeding is the presence of blood stains or smears on toilet tissue paper. When bleeding is greater, actual blood or blood-stained stool can be seen in the toilet bowl. It is important to take note of the colour of the blood as it indicates where the bleeding might be coming from.

  • Bright red or fresh blood may point to a bleeding source in the lower gastrointestinal tract such as the colon or rectum;
  • Dark red or maroon-coloured blood may point to bleeding in the small intestine or proximal colon;
  • Black and tarry stools is indicative of bleeding in the stomach or small intestine


Additional symptoms may include anal, pelvic or abdominal pain, dizziness, fatigue, diarrhoea, and constipation amongst others. Most cases of rectal bleeding will stop without treatment, but one should seek medical help as it may be a sign of a serious underlying condition that warrants attention.

How is rectal bleeding diagnosed?

Your doctor will seek more details such as when the bleeding first started, the frequency, the colour of the blood, and whether there are additional symptoms. These questions would help narrow down possible causes of your rectal bleeding, but further tests and procedures are generally required. Some of these procedures include:

  • Endoscopic procedures: a small camera is attached to a long flexible tube that is inserted into the rectum. This will allow the doctor to view the inside of the colon and identify any abnormalities. There are two different types of procedures – sigmoidoscopy, which is used to view the lower colon and rectum, and colonoscopy, which looks inside the large intestine.
  • Visual or physical examination: this may involve your doctor inserting a gloved and lubricated finger into the anus to check for abnormalities.
  • Fecal occult blood test: a lab test used to detect hidden blood in stool. This can be done by collecting stool samples to be given to the doctor.
Haemorrhoid surgery must be performed under general anaesthesia as the anal canal and skin around the anus is highly sensitive and packed with pain receptors.

What are the treatment options?

Treatment is tailored according to the cause and severity of the rectal bleeding. For example, small haemorrhoids may be treated with oral medications followed by a change of lifestyle that includes sufficient dietary fibre and fluids. Anal fissures can be treated with medications to ease constipation and enhance mucosal healing. In the case of more serious causes such as colon cancer, major surgery and additional treatment is necessary.
If you are experiencing rectal bleeding, avoid further delays and make an appointment with Thomas Ho Surgery today. It is better to be prudent than be sorry later.

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