The rectum is the last part of the large intestine present just above the anus. Rectal bleeding is referred to as bright red to dark maroon coloured blood passing along with stools through the anus. The amount of blood loss varies from mild traces to severe life-threatening bleeds. Bleeding can occur from any part of the gastrointestinal tract due to various causes.
Following are common causes of rectal bleeding:
- Piles (haemorrhoids) are the swollen blood vessels found in and around the rectal region. These can cause bleeding when passing stools and irritate the surrounding skin making you feel uncomfortable.
- Anal Fissure is a small painful tear in the tissue lining of the anus.
- Angiodysplasia of the colon is related to aging and occurs due to enlarged blood vessels in the colon.
- Gastroenteritis: Viral or bacterial stomach infection causing bloody diarrhoea with abdominal cramps and vomiting.
- Diverticula: Refers to tiny bulges that develop on the intestinal lining. The deteriorated blood vessels in the diverticula may burst or bleed.
Other conditions such as stomach ulcers, ulcerative colitis, Crohn’s disease and cancer of the colon or rectum may also cause rectal bleeding.
Signs & Symptoms
The colour of blood and consistency of stools varies depending on the location and the cause of bleeding in the gastrointestinal tract. The colour of stool may vary from bright red to maroon to dark red or black. A stool blood test may be required in cases of mild bleeding that is invisible to the naked eye.
Abdominal pain, visible blood clots or bleeding without pain are the typical symptoms associated with rectal bleeding. You may also experience weakness, chest pain, dizziness, shortness of breath, or blood pressure variations based on the amount of blood loss.
Do not ignore any type of bleeding in the stools. Rectal bleeding can occur due to a mild condition like piles or a more severe condition that may require immediate intensive treatment to control it.
Screening & Diagnosis
The diagnosis of rectal bleeding depends to a large extent on the patients’ age and medical history. Your doctor may ask questions about the bleeding such as the colour of blood, amount of blood loss or other associated symptoms. A physical examination of the anus can confirm the presence of anal fissures or haemorrhoids and helps to rule out other associated diseases.
Some diagnostic tests may be ordered to determine the cause of rectal bleeding and may include:
- Faecal occult blood test to check for small traces of blood present in the stools which is invisible to the naked eye. Changes in the colour of stool after adding a certain chemical to the test sample indicates the presence of blood in the stool.
- Anoscopy is an evaluation of the rectum in which a lubricated flexible tube (anoscope) is inserted into the rectum through the anus to detect abnormalities such as haemorrhoids and anal fissures.
- Flexible sigmoidoscopy uses a flexible sigmoidoscope to examine the sigmoid colon and the rectum.
- Colonoscopy is a procedure to evaluate the colon for polyps, cancer, ulcerative colitis and Crohn’s disease.
- Radionuclide scan is used to determine the location of gastrointestinal bleeding. A radioactive substance is injected and a nuclear camera is used to scan the stomach. The area affected with Meckel's diverticulum will concentrate the radioactive substance and show up on the scan. Another method involves attaching the radioactive substance to the blood of the patient and injecting the blood back into the veins. The tagged blood cells will leak into the bleeding area of the gastrointestinal tract and appear on the scan.
- Visceral angiogram uses X-rays to study the blood vessels of the digestive tract. This is an accurate test to locate rapid bleeding in the digestive tract.
Rectal bleeding can effectively be treated depending upon the related cause and underlying diagnosis.
- Treatment of anaemia
Your doctor will treat anaemia and decreased blood volume caused due to severe rectal bleeding by injecting intravenous fluids or by blood transfusions. Iron supplements will be prescribed to build up your iron levels.
- Haemorrhoidal creams and stool softeners may be prescribed to treat rectal bleeding associated with anal fissures or haemorrhoids.
- Medications to relieve pain or vasoconstrictors (decreases the size of blood vessels) to stop bleeding.
- Endoscopy can be used to stop bleeding by constricting or cauterizing the actively bleeding blood vessels.
- Constriction is achieved by infusion of medications through the endoscopic needle at the site of bleeding.
- Cauterization during endoscopy is usually accomplished by inserting a cautery probe through the endoscope.
- Surgery may be recommended to remove polyps, haemorrhoids, or tumours.
The most effective preventive measures of rectal bleeding include:
- Increase intake of fluids and eat a high fibre diet to avoid constipation.
- Avoid excessive alcohol consumption.
- You should seek immediate medical care if you notice blood in your stools.