What Is a Colonoscopy?

Colonoscopy is an important diagnostic test used to examine the large intestine (colon). It helps doctors identify the cause of various digestive problems and plays a crucial role in the early detection of colon diseases, including cancer.

In this blog, Dr. Vikas Singla explains what colonoscopy is, who needs it, how to prepare for it, and what to expect during and after the procedure.

What Is a Colonoscopy?

A colonoscopy is a medical test in which a doctor examines the inner lining of the colon using a thin, flexible tube fitted with a camera and light. This allows a detailed view of the rectum and the entire large intestine, and in some cases, the lower part of the small intestine (ileum).

Who Should Get a Colonoscopy?

A colonoscopy is recommended in several situations, including:

1. Blood in Stool

If a person notices blood in their stool, a colonoscopy is advised to check for wounds, polyps, or tumors in the colon.

2. Iron Deficiency Anemia in Older Adults

In older age, iron deficiency anemia can sometimes be caused by tumors in the colon. Colonoscopy helps identify the underlying reason.

3. Positive Occult Blood Test

Occult blood refers to blood in the stool that is not visible to the naked eye and is detected only through laboratory tests. A positive result is an indication for colonoscopy.

4. Chronic Constipation or Diarrhea

If constipation or diarrhea does not improve with medications, a colonoscopy may be required to find the cause.

5. Screening After Age 50

After the age of 50, screening colonoscopy is recommended even without symptoms. This helps detect problems early and significantly reduces the future risk of colon cancer.

6. Persistent Abdominal Pain

Patients with ongoing pain around the navel or in the lower abdomen that does not respond to medicines may need a colonoscopy for further evaluation.

How to Prepare for a Colonoscopy

Proper preparation is essential for an accurate colonoscopy.

• Diet Changes:
  One day before the procedure, solid foods are avoided. Only clear liquids are allowed for dinner.
• Laxatives:
  Medicines (laxatives) are given to clean the large intestine. After taking them, stools become watery, indicating that the colon is being cleaned.
• Duration of Preparation:
  Laxatives usually start one day before the test and continue until the stool becomes completely clear.
• Regular Medicines:
  Essential medicines can usually be continued on the day of colonoscopy.
  Patients taking blood thinners may need to stop or replace them temporarily, as advised by the doctor.

How Is Colonoscopy Performed?

Colonoscopy is done in a specialized endoscopy room.

• The patient lies comfortably on a couch.
• A sleep injection (sedation) is given to ensure the procedure is painless.
• Once the patient is asleep, the doctor inserts the colonoscope through the rectum.
• The camera helps examine the rectum, left colon, transverse colon, right colon, and sometimes the ileum.

If any abnormal area is found:

• A biopsy can be taken safely.
• Polyps can be removed during the same procedure.

What Happens After Colonoscopy?

After the procedure:

• The patient is shifted to a recovery room.
• Observation is done for 1–2 hours.
• Once fully awake and stable, the patient can go home.

Before discharge, the doctor discusses the findings with the patient and family in detail.

If a biopsy is taken, the report usually takes 4–5 days, which is discussed later during an OPD visit.

Is Colonoscopy Painful?

Colonoscopy is generally a painless procedure due to sedation.
Some patients may experience:

• Mild gas
• Slight abdominal discomfort

These symptoms are temporary and usually resolve on their own. Painkillers can be taken if discomfort is more noticeable.

Because the effect of sedation can last for several hours:

• Patients should not drive
• Avoid going alone
• Take rest at home for the day

Conclusion

Colonoscopy is a safe and effective test that helps diagnose and prevent serious colon-related diseases. Early detection through timely colonoscopy can significantly improve outcomes, especially in preventing colon cancer.