What Is a Colonoscopy?

A colonoscopy is a test that allows a doctor to look inside your large intestine (colon and rectum) using a thin, flexible tube with a small camera.

It is one of the most useful tests for finding problems such as colon polyps, bleeding, inflammation and colorectal cancer.

The important point is that a colonoscopy is not only done when someone has symptoms. In many people, it is performed as a screening test to detect colorectal cancer before symptoms appear.

When Should You Have a Colonoscopy?

There is no single age or schedule that is right for everyone.

Your doctor may recommend a colonoscopy based on:

• Your age

• Your symptoms

• Your family history

• Previous colon polyps

• Previous colonoscopy results

• Certain bowel diseases

• Other risk factors for colorectal cancer

Let's look at the most common situations.

1. For Routine Colorectal Cancer Screening

For people at average risk of colorectal cancer, screening generally begins around age 45.

If the colonoscopy is normal, the next examination is often recommended approximately 10 years later.

However, this interval applies to people who are considered average risk and have a high-quality normal examination. It may be shorter if polyps are found or if you have additional risk factors.

Screening can detect precancerous polyps, which can often be removed during the same procedure before they have the opportunity to develop into cancer.

2. If You Have Blood in Your Stool

Blood in the stool should never simply be assumed to be piles.

Possible causes include:

• Hemorrhoids

• Anal fissure

• Colon polyps

• Inflammatory bowel disease

• Diverticular disease

• Colorectal cancer

• Other gastrointestinal conditions

Depending on your age, symptoms and risk factors, your doctor may recommend a colonoscopy to identify the source of bleeding.

Visible blood in the stool, especially when persistent or unexplained, deserves medical evaluation.

3. If Your Bowel Habits Have Changed

A persistent change in bowel habits can sometimes be a warning sign.

Examples include:

• New constipation

• Persistent diarrhoea

• Alternating constipation and diarrhoea

• A noticeable change in stool pattern

• Feeling that your bowel does not completely empty

• A persistent change in stool calibre

Most bowel changes are not caused by cancer. Diet, infections, medications and several other conditions can cause similar symptoms.

However, a new and persistent change should be assessed rather than ignored.

4. If You Have Unexplained Weight Loss or Anaemia

Unintentional weight loss is a symptom that deserves attention, particularly when it occurs together with bowel symptoms.

Similarly, iron-deficiency anaemia may sometimes be caused by slow, unnoticed bleeding from the gastrointestinal tract.

In these situations, your doctor may recommend colonoscopy to look for a possible source of bleeding or other abnormalities.

5. If You Have a Family History of Colon Cancer

Your screening may need to begin earlier than usual if a close family member has had colorectal cancer or certain types of advanced polyps.

The exact timing depends on factors such as:

• Which relative was affected

• Their age when diagnosed

• Whether multiple family members are affected

• Whether there is a known hereditary cancer syndrome

If colorectal cancer runs in your family, tell your doctor rather than simply following the routine screening schedule.

6. If You Previously Had Colon Polyps

Finding a polyp does not automatically mean that you have cancer.

However, some types of polyps can gradually develop into cancer.

If polyps were removed during a previous colonoscopy, your doctor will recommend a surveillance colonoscopy based on:

• Number of polyps

• Size of polyps

• Type of polyp

• Microscopic examination

• Completeness of removal

• Quality of the previous colonoscopy

Therefore, someone who has previously had polyps may need colonoscopy more frequently than someone with a completely normal examination.

7. If You Have Inflammatory Bowel Disease

People with long-standing ulcerative colitis or Crohn's disease involving the colon may require regular colonoscopic surveillance.

This is different from routine screening because chronic inflammation of the colon can increase the long-term risk of colorectal cancer.

Your gastroenterologist will determine the appropriate surveillance schedule based on the duration and extent of disease and other risk factors.

What Happens During a Colonoscopy?

Before the procedure, your colon needs to be thoroughly cleaned.

This requires taking a prescribed bowel-preparation solution and following specific dietary instructions.

During the colonoscopy:

1. You are usually given sedation or anaesthesia according to the planned procedure.

2. A flexible camera is gently introduced through the anus.

3. The doctor examines the rectum and entire colon.

4. Polyps can be removed if identified.

5. Small tissue samples (biopsies) can be taken when necessary.

6. The procedure is completed and you are monitored during recovery.

The procedure itself is generally well tolerated because sedation is commonly used.

Can Polyps Be Removed During the Same Colonoscopy?

Yes.

One of the major advantages of colonoscopy is that it is both a diagnostic and therapeutic procedure.

If a suitable polyp is found, it can often be removed during the same examination.

The tissue is then sent to a laboratory for microscopic examination.

This is one reason colonoscopy can help prevent colorectal cancer, rather than simply detect it after cancer has developed.

Is Colonoscopy Safe?

Colonoscopy is generally a safe procedure when performed by an appropriately trained team.

However, like any medical procedure, it has potential risks.

These can include:

• Bleeding, particularly after polyp removal

• Abdominal discomfort or bloating

• Reaction to sedation

• Rarely, perforation of the colon

The risk varies depending on the patient's health and what is done during the procedure.

Your doctor will discuss the relevant risks and benefits before the examination.

How Often Do You Need a Colonoscopy?

There is no universal schedule.

For an average-risk person with a normal, high-quality colonoscopy, a repeat examination is commonly recommended after about 10 years.

But the interval may be much shorter if:

• Polyps are detected

• Polyps have concerning features

• You have a family history of colorectal cancer

• You have inflammatory bowel disease

• Your previous colonoscopy was incomplete

• The bowel preparation was inadequate

• You have ongoing symptoms

Your previous colonoscopy report and pathology report are therefore very important when deciding when the next examination is needed.

Do You Need a Colonoscopy If You Have No Symptoms?

Yes, potentially.

This is an important point.

Waiting until symptoms develop defeats the purpose of cancer screening.

Colorectal cancer can develop from precancerous polyps over time, and early disease may produce no obvious symptoms.

Screening allows doctors to find and remove certain precancerous lesions before they become cancerous.

Colonoscopy Is Not Only About Cancer

Although colorectal cancer screening is an important reason for colonoscopy, the procedure can also help diagnose:

• Polyps

• Unexplained gastrointestinal bleeding

• Inflammatory bowel disease

• Diverticular disease

• Certain causes of chronic diarrhoea

• Other abnormalities of the colon

Your doctor decides whether colonoscopy is appropriate based on your individual symptoms and medical history.

About SIDS Hospital

SIDS Hospital & Research Centre, Surat, provides comprehensive gastrointestinal and surgical care, including evaluation and management of colorectal and gastrointestinal diseases.

If you have persistent bowel symptoms, blood in the stool, unexplained anaemia, or concerns about colorectal cancer screening, consult a qualified gastrointestinal specialist for an individualized assessment.