Colonoscopy

Colonoscopy is performed for the following reasons:

• Colorectal cancer screening
  • Diagnostic
  • Therapeutic
• Investigation of the causes of
  • Rectal bleeding
  • Unexplained abdominal pain
  • Pain or mucus in stool
  • Change in bowel habits
  • Acute or chronic anaemia
• History of gastrointestinal cancer or colon or rectal polyps
• Inflammatory bowel diseases, such as Crohn’s disease and ulcerative colitis
• Familial hereditary conditions, such as nonpolyposis colorectal cancer or Lynch Syndrome
• Follow-up after a procedure

The goal of a screening programme is to detect diseases as early as possible for initiating treatment.

Colonoscopy screening is routinely recommended every 10 years in adults aged 50 years and older; individuals with a family history of colorectal cancer may be screened from the age of 45 years.

Proper planning and preparation are required before undergoing a colonoscopy procedure. The goal of preparation is to keep the colon free of solid foods for clear visualisation.

• Liquids and low-fibre diet are recommended. Red-coloured liquids are prohibited as they may be confused with blood during the procedure.
• All medications that are being taken should be noted and recorded. Special care should be taken regarding blood thinners, as perforation and bleeding are potential complications. Drug dosages may be modified or stopped before the test.
• All solid foods are avoided, and a liquid diet is followed a day before the procedure. Medications are given to cleanse the bowel. A laxative or enema is prescribed to empty the colon. If bowels are not completely empty, the whole procedure may have to be repeated.
• Passage of liquid stools may cause skin irritation, which can be managed by using moist wipes and ointments.
• Laxatives used may cause dehydration, hence proper hydration should be maintained. Large amounts of water should be consumed prior to the procedure.

Preparation, procedure and recovery from colonoscopy take around 3 hours, but the test itself lasts for about 15–20 minutes.

• The individual will need to change into a hospital gown before the procedure.
• An intravenous line is introduced into the back of the hand for access to medications and sedation.
• After the individual is given a sedative and is relaxed, he/she is made to lie on the left side, knees tucked up to the chest.
• The inner lining of the large intestine is examined by inserting a colonoscope through the rectum. Air or carbon dioxide is introduced through the scope to provide a better view. When the scope reaches the point where the colon joins the small intestine, it is gently withdrawn and the lining is examined again.
• Colonoscope contains a camera, which helps navigate access through the colon and capture images. An instrument channel is also present, which allows tissue samples to be removed or taken for biopsy.

After the procedure, it takes around an hour to recover from sedation. Driving and other complicated tasks should be avoided until then. One may also have bloating or gas for a few hours. Walking around will ease the discomfort. A normal diet is to be resumed unless otherwise instructed. If a biopsy or excision has been done, the doctor will advise when to start retaking blood thinners. A small amount of blood may be present in stools for one or two days.

Complications are uncommon after a colonoscopy. Severe abdominal pain, fever and chills or rectal bleeding may be the symptoms of

• Excessive bleeding from biopsy or polyp removal
• Perforation of the colon wall
• Infection

Biopsy results and images taken during the procedure both contribute to the results.

Normal results: A colonoscopy is considered normal or negative when no abnormalities are found. A repeat colonoscopy may be recommended depending on the history of the individual, risk of cancer and colonoscopy findings.

Abnormal results: Presence of polyps or abnormal tissue indicates an abnormal or a positive result. Number, size, location of abnormal growths and their biopsy results determine whether the polyp is cancerous or precancerous. Repeat procedures are recommended when large or multiple and cancerous polyps are found.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. This information is purely from an educational perspective and is in no way a substitute for medical advice from a qualified doctor.