Colonoscopy is one of the primary tools used for colon cancer screening and is widely considered to be the most effective method for it. This procedure takes a look inside the colon and examines its lining using a long, soft and flexible tube with a tiny camera and light attached on the end. This enables live viewing and visual images of the entire large bowel and lower part of the small intestine to be displayed on the screen.
How does this procedure take place?
Colonoscopy helps doctors to directly visualize the colonic mucosa and identify anycolonic polyp growths that occur on the inside wall of the colon or rectum. If detected, pre-cancerous lesions such as tubular adenomas will be removed during the colonoscopy, thus preventing colon cancer.
The bowel preparation is an important component of the colonoscopy as it impacts the success of colonoscopy. It involves fasting for at least 6 hours before undergoing colonoscopy along with medication to help you pass motion. A bowel preparation that is optimal results in increased polyp detection and decreased procedure time. Inadequate prep can lead to variability when interpreting colonoscopy results whereby certain lesions such as polyps or cancers can be potentially missed due to improper bowel cleanliness.
What else is colonoscopy used for?
Apart from colon cancer prevention, this procedure is also a safe and effective method to investigate symptoms in the digestive system and is essential to help in the management of several gastrointestinal illnesses.
Colonoscopy may be used to investigate digestive symptoms such as:
- Chronic diarrhoea
- Abdominal pain or bloatedness
- Blood in stool
- Change of bowel habits
- Unexplained weight loss
- Chronic constipation
Colonoscopic examination may also be used in some colonic illnesses such as:
- Ulcerative colitis
- Colonic polyp
- Crohn’s disease
- Angiodysplasia of the colon
Why does the quality of colonoscopy matter?
Colonoscopy is performed by specialists, specifically gastroenterologists. They undergo specialised training to carry out the procedure and diagnose various diseases skilfully.
The recommended quality colonoscopy is measured by the specialist’s detection of adenomatous polyps at least at a rate above 25% and a cecal intubation rate above 95%. This makes a significant difference in improving outcomes of detecting polyps and increasing diagnostic accuracy.
Cecal intubation rate refers to intubating the cecum whereby the colonoscope is passed through the ileocecal valve to examine the medial wall of the cecum. The rate is determined by the complete examination of the colon – incomplete coloscopies may be caused by poor bowel preparation, severe colitis or other reasons.
Adenoma detection rate (ADR) involves the proportions of patients over 50 years old who undergo screening colonoscopies for the first time in which at least one adenomatous polyp is detected in a given time period for a given specialist. ADR is a relevant quality indicator that is reported to be significantly associated with the risk of interval cancers or post-colonoscopy cancers, and directly measures how effective the colonoscopy that the gastroenterologist offer is.
Aside from proper bowel preparation to provide a clear view of potential problems, knowing the specialist’s ability to find polyps more often than others is crucial. It can mean the difference between detecting an early sign of colon cancer and missing it. A doctor’s effective removal in detecting and removing– pre-cancerous polyps gives patients added confidence to undergo the procedure and reduce the anxiety of potentially developing cancer.
Ultimately, the quality of colonoscopy will increase the colonoscopy value and lead to further decreases in the incidence and mortality of colon cancer. This is dependent on the level of experience and expertise of the gastroenterologist in conducting colonoscopies.