Call Us

Contact Us

Colonoscopy: When and Why Do You Need One?

woman physician smiling

Colonoscopy is a valuable medical procedure that plays a crucial role in the early detection and prevention of colorectal cancer, one of the most common and deadly cancers worldwide. However, many individuals may wonder when and why they need a colonoscopy.

In this article, we will explore the importance of colonoscopy, the guidelines for its timing, and the reasons to consider this life-saving procedure.

Understanding Colonoscopy

Colonoscopy is a diagnostic and therapeutic procedure performed by a gastroenterologist or a general surgeon. During a colonoscopy, a long, flexible tube with a tiny camera at the end is inserted into the rectum and advanced through the entire colon.

This procedure allows the physician to visually examine the colon’s lining and identify any abnormalities, such as polyps or tumors. Colonoscopy serves multiple purposes, making it an invaluable tool in the field of medicine.

Early Detection of Colorectal Cancer

Colorectal cancer is the second leading cause of cancer-related deaths in the United States. Colonoscopy is highly effective in detecting colorectal cancer at an early, treatable stage. By identifying precancerous polyps and early-stage cancers, it provides a chance for timely intervention and improved outcomes.

Polyp Removal

During a colonoscopy, polyps may be removed. Polyps are abnormal growths on the inner lining of the colon and rectum, and some of them can turn into cancer over time. By removing these polyps during the procedure, the risk of developing colorectal cancer is significantly reduced.

Investigating Unexplained Symptoms

Besides cancer screening, colonoscopy is used to investigate unexplained symptoms or conditions affecting the colon or rectum. Some common indications for diagnostic colonoscopy include:

Gastrointestinal Bleeding

If you experience unexplained rectal bleeding or find blood in your stool, a colonoscopy can help identify the source of the bleeding.

Persistent Abdominal Pain

Chronic abdominal pain or discomfort, especially if it is associated with changes in bowel habits, may necessitate a colonoscopy to rule out colon-related issues.

Change in Bowel Habits

Sudden changes in bowel habits, such as prolonged diarrhea or constipation, can be symptoms of underlying colon problems that require investigation.


Unexplained anemia may be a sign of gastrointestinal bleeding, which can be evaluated through a colonoscopy.

Timing of a Colonoscopy

The timing of a colonoscopy depends on several factors, including your age, medical history, and family history of colorectal cancer or polyps. Understanding when you should consider a colonoscopy is essential for early detection and prevention.

Age-Based Recommendations

Age is a significant determinant in the timing of your first colonoscopy. For individuals with no known risk factors, the following age-based recommendations typically apply:

Average Risk

Most individuals should start considering colonoscopy at age 50. This initial colonoscopy serves as a baseline examination.

High-Risk Groups

If you have a family history of colorectal cancer or polyps, especially in first-degree relatives, or if you have a personal history of inflammatory bowel disease (IBD), you may need a colonoscopy earlier than the age of 50. Consult with your healthcare provider to determine the appropriate timing.
Screening Intervals
The frequency of colonoscopy screenings varies based on your initial findings and risk factors:

Normal Colonoscopy

If your initial colonoscopy reveals no abnormalities, you may not need another colonoscopy for ten years, assuming you have no risk factors.

Small Polyps

If small, low-risk polyps are removed during your colonoscopy, you may require another colonoscopy in 5-10 years, depending on your healthcare provider’s recommendation.

High-Risk Findings

If significant polyps or other abnormalities are discovered, your doctor may recommend more frequent screenings, often every 3-5 years.

Family History Considerations

Your family history of colorectal cancer or polyps is a critical factor in determining when to undergo a colonoscopy:

  • Family History of Colorectal Cancer. If you have a first-degree relative (parent, sibling, or child) with a history of colorectal cancer, your screening should typically begin at an age ten years younger than the relative’s age at diagnosis.
  • Family History of Polyps. If you have a family history of adenomatous polyps (a type of polyp that can become cancerous), your healthcare provider may recommend starting screening earlier and more frequently.
  • Genetic Syndromes. In families with specific genetic syndromes, such as familial adenomatous polyposis (FAP) or Lynch syndrome, screening should begin earlier and occur more frequently.

Reasons for a Colonoscopy

In addition to age and family history, several medical reasons may necessitate a colonoscopy. These include:

Previous Abnormal Test Results

If you have had abnormal results from other colorectal cancer screening tests, such as a fecal occult blood test (FOBT) or a sigmoidoscopy, a colonoscopy may be recommended for further evaluation. Anemia in the elderly without a clear cause may also require a colonoscopy.

Unexplained Gastrointestinal Symptoms

As mentioned earlier, unexplained symptoms like gastrointestinal bleeding, abdominal pain, or changes in bowel habits may warrant a diagnostic colonoscopy.

Follow-Up After Previous Polyps

If you have had polyps removed during a previous colonoscopy, your doctor will recommend follow-up colonoscopies to monitor and prevent the development of new polyps.

Inflammatory Bowel Disease

Individuals with inflammatory bowel diseases, such as Crohn’s disease or ulcerative colitis, have an increased risk of developing colorectal cancer. Regular colonoscopies are often recommended for early cancer detection in this high-risk group.


Colonoscopy is a powerful tool for the early detection and prevention of colorectal cancer, a disease that remains a significant health threat. Understanding when and why you need a colonoscopy is essential for maintaining your health.

Age-based recommendations, family history, previous test results, and unexplained symptoms all play a role in determining the timing of this life-saving procedure.

By following the appropriate guidelines and consulting with your healthcare provider, you can take proactive steps towards preventing colorectal cancer and ensuring your long-term well-being.

Introducing Curasia Endoscopy Centre

Our host, Jerald Foo, will be taking you to our first centre at Jurong East.

Make An Enquiry

Leave us your details and we’ll get back to you shortly.
Prefer to talk? Call our clinic directly to make an enquiry at +65 6679 1229

or Whatsapp us at +65 9750 8783

We are available 24 hours

Let's Get in Touch!

Clinic Details

Other Related Articles

insurance papers with money and stethoscope
Endoscopy Cost

Claiming Endoscopy Costs from Medisave

Endoscopy procedures, such as gastroscopy and colonoscopy, are essential for diagnosing various gastrointestinal conditions. In Singapore, these procedures can be quite costly, making it important

Read More
Curasia Endoscopy

Call Us

Contact Us