What is a Colonoscopy?

A colonoscopy is an endoscopic examination of the large bowel using a colonoscope, a thin, flexible tube with a light and camera. It is the gold standard for identifying issues like colorectal cancer, polyps, and ulcers. The procedure is performed under sedation to ensure maximum comfort.

While all medical procedures carry some risk, the risks of colonoscopy in experienced hands are very low. The American Society for Gastrointestinal Endoscopy estimates that only three out of 1,000 colonoscopies lead to complications.

The benefits of a colonoscopy far outweigh the rare risks. Colonoscopy reduces the risk of colorectal cancer by removing precursor lesions (polyps) and increases the likelihood of curative treatment through early detection of colorectal cancer, which may not yet show symptoms.

Why Do I Need a Colonoscopy?

A colonoscopy may be necessary to:

• Investigate unexplained changes in bowel habits

• Evaluate symptoms like abdominal pain or rectal bleeding

• Rule out colonic conditions that could explain unexplained weight loss or appetite loss

• Follow up on previous disease

• Assess the clinical importance of an abnormality seen on an imaging scan

Colonoscopy Screening: Why Do I Need One If I Have No Symptoms?

Colorectal cancer is the most common cancer in Singapore. Between 2017 and 2021, 12,239 cases of colorectal cancer were diagnosed. Men, particularly Chinese men, are at a higher risk. Surgery is the primary treatment for colorectal cancer, and early diagnosis through colonoscopy improves the chances of a cure.

Most colorectal cancers begin as adenomatous polyps. The transformation of these polyps into cancer (adenoma-carcinoma sequence) can take 3 to 10 years through multiple gene mutations. Adenomatous polyps cause no symptoms and are present in up to 25% of people by age 50, with the prevalence increasing with age. Most polyps can be removed during a colonoscopy, preventing the need for surgery.

Mortality from colorectal cancer can be reduced by screening asymptomatic individuals, identifying, and removing polyps before they turn into cancer. The American Cancer Society recommends that individuals at average risk of colorectal cancer begin regular screening at age 45.

In Singapore, screening should begin at age 50 for people without risk factors. For those with increased risks, such as a family history of cancer, screening may begin before age 50, depending on the specific risk factors.

Whether through stool-based tests or visual examinations like colonoscopy, both have their differences, but the most important point is to get screened.

Feel free to talk to us in clinic for in-depth advice.