What are the methods of 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.