What is Colonoscopy
A colonoscopy is a medical procedure that allows doctors to examine the inside of the colon (large intestine) using a flexible tube with a camera on the end, called a colonoscope. It is commonly used for screening, diagnosis, and sometimes treatment of conditions like colon cancer, polyps, inflammatory bowel disease, and bleeding in the gastrointestinal tract.
What to Expect During a Colonoscopy
During the procedure, the colonoscope is gently inserted through the rectum into the colon.
The camera transmits images to a monitor, allowing the doctor to visually inspect the lining of the colon.
The procedure is usually performed under sedation or light anaesthesia, so most patients remain comfortable.
Why is a Colonoscopy Done?
Colonoscopy is used for:
Screening for colon cancer, especially if you are over 50 or have risk factors like family history.
Diagnosing symptoms like abdominal pain, unexplained weight loss, chronic diarrhoea, or rectal bleeding.
Monitoring patients with a history of polyps or inflammatory bowel disease (e.g., Crohn’s disease, ulcerative colitis).
Removing polyps or taking biopsies if any abnormal tissue is seen.
Preparing for a Colonoscopy
Proper preparation is essential to ensure clear visibility during the procedure. Preparation usually involves the following steps:
1. Dietary Changes (24-48 Hours Before)
Low-fibre diet: Start a low-fibre diet 2 days before your colonoscopy. Avoid whole grains, nuts, seeds, fruits, and vegetables.
Clear liquids only: The day before your procedure, switch to a clear liquid diet. This includes water, clear broths, tea, coffee (without milk), clear juices (like apple or white grape juice), and gelatine (no red or purple colours).
Avoid red or purple liquids: These colours can be mistaken for blood during the exam.
2. Bowel Preparation (Laxatives)
You will be given a laxative solution to empty your bowels. This is often taken in two doses: one the evening before the procedure and the other several hours before.
Follow your doctor's instructions precisely, as timing and dosage are important for effective preparation.
Be prepared for frequent bowel movements after taking the laxative, so stay near a bathroom.
3. Adjusting Medications
Certain medications (e.g., blood thinners, diabetes medications) may need to be adjusted before the procedure. Always inform your doctor about any medications and supplements you are taking, so they can provide guidance on which to continue or stop.
Avoid non-steroidal anti-inflammatory drugs (NSAIDs) and iron supplements in the days leading up to the procedure, as these may affect the preparation process or cause bleeding.
4. Day of the Procedure
Do not eat or drink anything on the morning of the colonoscopy, except for small sips of water if necessary.
Wear comfortable clothing, and bring any paperwork or identification required.
Arrange for someone to accompany you home, as you will be sedated and unable to drive after the procedure.
Post-Colonoscopy Recovery
After the procedure, you may experience mild bloating, cramping, or gas. Most patients can resume their usual diet and activities within a day. Your doctor will provide specific post-procedure instructions based on what was done during the colonoscopy.
References for Further Reading
NHS Guide on Colonoscopy
NHS - Colonoscopy
American Cancer Society - Guide to Colonoscopy
American Cancer Society - Colonoscopy
American Society for Gastrointestinal Endoscopy - Colonoscopy Preparation
ASGE - Colonoscopy Preparation