What is a Screening Colonoscopy?
Colorectal cancer stands as a formidable adversary, ranking among the leading causes of cancer-related deaths worldwide. According to the Singapore Cancer Registry Annual Report 2019, colorectal cancer is the number 1 and 2 types of cancer for men and women in Singapore. It is estimated that the lifetime risk of getting colorectal cancer is 5.6% (about 1 in 20 people). This cancer, affecting the colon or rectum, often develops without noticeable symptoms in its early stages. Consequently, the significance of early detection and prevention cannot be overstated. In this light, screening colonoscopy is essential in the proactive battle against colorectal cancer.
A screening colonoscopy is a medical procedure designed for the early detection of colorectal cancer and for preventing its progression. During this minimally invasive examination, a flexible, slender tube equipped with a tiny camera is gently inserted into the colon and rectum.
This instrument, known as a colonoscope, allows healthcare professionals to visually inspect the inner lining of the large intestine, identifying and removing precancerous polyps before they have the chance to develop into cancer.
How it Differs from Diagnostic Colonoscopy
While screening and diagnostic colonoscopies involve using a colonoscope, they serve distinct purposes. A screening colonoscopy is conducted in asymptomatic individuals for colorectal cancer, aiming to detect and prevent the disease in its early stages.
On the other hand, a diagnostic colonoscopy is performed when there are specific symptoms, such as gastrointestinal bleeding or unexplained abdominal pain, prompting further investigation into the cause.
Recommended Age and Frequency for Screening
The recommended age to initiate screening colonoscopy use to be 50 years old. However due to an alarming trend of rise in people being diagnosed with colorectal cancer under the age of 50, recent guidelines recommend for screening to start at age 45 for an average risk individual. However, certain factors, including family and personal health history, may influence the timing of the first screening.
In frequency, individuals are typically advised to undergo a colonoscopy every 10 years, although more frequent screenings may be recommended for those with higher risk profiles. Regular screenings are vital for early detection and intervention, significantly reducing the risk of colorectal cancer development.
What are Alternatives to Screening Colonoscopy for Colon Cancer Screening?
In addition to screening colonoscopy the following tests are available:
- Faecal Occult Blood Test (FOBT) and Fecal Immunochemical Test (FIT) – These are non-invasive tests that detect traces of blood in the stool, which can be a sign of colon cancer. FOBT uses a chemical reaction to detect blood, while FIT uses antibodies specific to human blood. Further evaluation, such as a colonoscopy, is usually recommended if blood is detected.
- Sigmoidoscopy – Similar to a colonoscopy, it examines only the lower part of the colon (sigmoid colon) and rectum.
- CT Colonography (Virtual Colonoscopy) – A CT scan creates detailed images of the colon and rectum, which can be examined for abnormalities. A follow-up colonoscopy may be required if polyps or suspicious findings are detected.
Preparation for a Screening Colonoscopy
Preparation for a Screening Colonoscopy involves a meticulous approach encompassing dietary adjustments, lifestyle modifications, and a crucial bowel preparation process.
Dietary and Lifestyle Guidelines
Proper preparation is key to the success of a screening colonoscopy. In the days leading up to the procedure, individuals are usually advised to follow a specific diet and make certain lifestyle adjustments.
This often involves limiting fibre intake and avoiding certain foods like seeds and nuts. Staying hydrated is crucial during this period. It is essential to adhere strictly to the provided guidelines to ensure a clear and unobstructed view of the colon during the examination.
Bowel Preparation Process
One of the critical aspects of preparing for a screening colonoscopy is bowel preparation. This typically involves taking a prescribed laxative or a combination of medications to cleanse the colon thoroughly.
Following the healthcare provider’s instructions on the timing and dosage is crucial to effective bowel preparation. While the process may be deemed inconvenient, it is necessary to ensure the examination results’ accuracy.
The Procedure
The screening colonoscopy is a crucial medical examination for detecting and preventing colorectal issues. Understanding the steps involved can help individuals prepare mentally and physically for the experience.
Check-In and Pre-Procedure Assessment
Patients typically check in at the medical facility on the day of the colonoscopy. A pre-procedure assessment, including vital signs and a medical history review, may be conducted.
Anesthesia Administration
Before the procedure begins, patients are usually administered a sedative or anaesthesia to ensure comfort and relaxation. Sometimes, a milder form of sedation may be used, allowing individuals to remain conscious but relaxed.
Positioning and Colonoscope Insertion
Patients are positioned on their left side as the colonoscope, a long, flexible tube with a light and camera, is gently inserted through the rectum. The colonoscope is advanced through the entire colon length, allowing the doctor to examine the lining for abnormalities carefully.
Visual Inspection and Biopsy
The camera on the colonoscope transmits real-time images to a monitor, enabling the doctor to inspect the colon’s interior visually. If any suspicious areas or polyps are identified, the doctor may perform a biopsy, collecting tissue samples for further analysis.
Air or Gas Insufflation
The colon may be inflated with air or carbon dioxide during the procedure to provide a clear view. This may cause temporary bloating or discomfort, but it helps the doctor navigate and visualise the colon more effectively.
Polyp Removal (if necessary)
If polyps are detected, they are often removed during the colonoscopy. This is a preventative measure to reduce the risk of colorectal cancer.
Completion of the Procedure
Once the examination is complete, the colonoscope is carefully withdrawn. The effects of sedation may linger briefly, and patients are usually monitored until they are fully awake and alert.
Post-Procedure Discussion
After the colonoscopy, the doctor discusses the findings with the patient. Further recommendations or follow-up plans are provided if any biopsies were taken or polyps removed. While the procedure itself is relatively short, lasting about 30 to 60 minutes, the entire process from check-in to discharge will take 3-4 hours.
Benefits of Screening Colonoscopy
Screening colonoscopy is a valuable medical procedure that offers various benefits regarding early detection, prevention, and overall colorectal health. Here are some key benefits.
- Early Detection of Precancerous Polyps – One of the primary benefits of a screening colonoscopy is the early detection and removal of precancerous polyps. These abnormal growths in the colon lining can, over time, develop into colorectal cancer. Identifying and removing polyps during the screening process significantly reduces the risk of cancer development. This proactive approach allows for timely intervention before the progression of potentially harmful conditions.
- Reduced Risk of Developing Colorectal Cancer – Regular screening of colonoscopies has been associated with a substantial reduction in the risk of developing colorectal cancer. Detecting and removing precancerous polyps early prevents their evolution into cancerous lesions. This reduction in the incidence of colorectal cancer underscores the preventive impact of screening colonoscopies, making them a crucial tool in the fight against this prevalent and potentially life-threatening disease.
- Improved Treatment Outcomes – Early detection through screening colonoscopies contributes to improved treatment outcomes for colorectal cancer. When cancer is identified in its early stages, treatment options are often more effective, less invasive, and associated with a higher likelihood of success. By undergoing regular screenings, individuals increase their chances of catching any potential issues before progressing to advanced stages, facilitating more favourable treatment outcomes.
Who Should Get a Screening Colonoscopy?
Age and Risk Factors
All patients between the ages of 45-75 and are in good health should be considered for screening. The decision to be screened between ages 76 and 85 should be made on an individual basis hence this should be discussed with your doctor. However, age is not the sole factor to consider.
Various risk factors, such as a personal history of inflammatory bowel disease, a previous colorectal cancer diagnosis, or a family history of colorectal issues, can influence when screening should commence. Healthcare providers assess these factors to determine an individualised screening schedule.
Family History and Genetic Considerations
Individuals with a family history of colorectal cancer or certain genetic conditions that predispose them to the disease may need to undergo screening at an earlier age and more frequently. Understanding one’s family history and discussing it with healthcare providers allows for tailored recommendations and a more proactive approach to colorectal health.
Every person is unique, and so are their health circumstances. Individualized recommendations for screening colonoscopies take into account a person’s medical history, risk factors, and overall health. The significance of screening colonoscopy cannot be overstated in the battle against colorectal cancer.
This proactive measure plays a pivotal role in the early detection and prevention of this potentially life-threatening disease. By identifying and removing precancerous polyps before they evolve into cancer, screening colonoscopies offers a powerful tool for maintaining optimal colorectal health.
