Colonoscopy procedure: What is it and how is it performed?

Colon-related diseases can lead to severe consequences, the most threatening of which is colon cancer. Colon cancer begins in the colon or large intestine and occurs when cells in this organ grow out of control. The early stages of abnormal colon cell behaviour manifest as polyp growth in the colon

Not all polyp growth progresses into colon cancer, but some eventually do. The best way to determine whether your colon is healthy and free of polyps is if you undergo a colonoscopy under the care of a gastroenterologist.

The prospect of a colonoscopy may be intimidating, and limited information about this procedure may cause more worry. Understanding the procedure and how it can help with your condition can provide a sense of comfort.

Colonoscopy procedure

During the process, the doctor will first give the patient certain intravenous medications that will make them feel relaxed and drowsy.

The patient will then be asked to lie on his/her left side on the examination table.

The doctor uses a long and flexible tube-like instrument called a colonoscope. It is inserted through the rectum and is moved towards the large intestine.

The colonoscope takes images of the inner lining of the colon for the doctor to look for the presence of abnormalities. Advanced technology such as Narrow Band Imaging technique (NBI) has been applied in detecting early-stage cancer.

Since the instrument is flexible and can bend, it allows the doctor to move it along the colon curves.

The doctor may also require the patient to shift positions during the process.

The instrument then blows air into the colon, which helps to expand it for the doctor to see clearly.

The doctor will remove small amounts of tissue for biopsy if he finds an abnormality.

Finally, the doctor slowly withdraws the instrument from the colon and continues examining the whole colon.

The whole colonoscopy procedure takes about 10-30 minutes.

What is colonoscopy used for?

Colonoscopy is used to detect possible abnormalities in the colon. Your gastroenterologist may use a colonoscopy to:

• Examine causes of signs and symptoms of intestinal or digestive conditions

  If you have been experiencing abdominal pain, chronic diarrhoea or constipation, rectal bleeding, or other colon problems, your doctor may investigate the causes through a colonoscopy.

• Check for colon cancer

  A colonoscopy is an option for screening for colon cancer. It is recommended that you begin undergoing regular colonoscopies at the age of 45, with your gastroenterologist determining the frequency of the procedure. They may request it be done sooner should they observe any strong indicators of cancer.

• Look for polyps

  Your gastroenterologist would check for polyps. In doing this, the polyps can be removed to send for a histopathology report.

Colonoscopy preparation

Your gastroenterologist will prepare you for your colonoscopy by ensuring you first understand the procedure. Expect them to provide you with appropriate painkillers or sedatives to help you relax during the procedure.

Before going to your gastroenterologist for your colonoscopy, do make sure that you have an empty bowel. Your gastroenterologist will prescribe a medication that helps in emptying your bowel a few hours to a day before the procedure.

Keep hydrated with water during bowel preparation. Drinking and eating are prohibited four hours prior to the procedure.

Making sure your colon contains no waste from consumed food or liquids is important. The cleaner your colon is during a colonoscopy, the more precise the detection of polyps or other signs of colon cancer can be.

A clean colon means that even the smallest polyp or signs of colon cancer can be identified at stages when they are still treatable.

After the procedure, you will be observed while you are recovering. You may experience passing gas in the hours after the procedure, but you should be able to return to your normal diet immediately.

Colonoscopy risks

Colonoscopy is usually a safe procedure. Studies have shown that the estimated overall risk of complications due to colonoscopy is low, about 0.1% to 1%. Some minor risks include:

• Belly pain and discomfort - this may include cramping and bloating post the procedure
• Bleeding - Small amounts of blood could ooze from the rectum into the stools. This could happen if the doctor had to take tissue samples for biopsy or had to remove some polyps. Call your doctor if the bleeding is excessive and does not stop
• Reaction to anaesthesia - Although rare, some people can have reactions to anaesthesia which include heart or breathing problems. Inform your doctor if you have pre-existing allergies to any medications or underlying health problems
• Postpolypectomy Electrocoagulation Syndrome - When the doctor needs to cut off a polyp, they use an electric current to seal the internal wound. In very rare cases, if the current goes too deep, it may cause inflammation and minor burns in the tissues, which can cause belly pain and fever
• Infection - In rare cases, the colonoscopy tools may be infected with bacteria which may get passed on to the patient
• Perforated intestine - Sometimes, the instrument may push rough against the colon, causing a small tear. The risk of perforation is higher while performing therapeutic procedure, especially polypectomy. The doctor may need to surgically repair it
• Precolonoscopy risks - Since the doctor needs to give certain medications before the procedure to empty the colon, it may result in risks like dehydration, and electrolyte imbalance

FAQ on colonoscopy

Is colonoscopy painful?

A very small percentage of people may experience some degree of abdominal cramping and discomfort after the process.

This is mostly because the doctor has had to use air to expand the intestines to get a clearer view. In other instances, where the doctor had to extract tissues for biopsy or remove polyps, some level of pain or mild discomfort can be experienced. However, most post-procedure pains are well managed by medications.

Is colonoscopy a serious procedure?

Yes, colonoscopy is a serious procedure. However, it is a very safe one. Doctors around the globe use it very frequently with successful outcomes.

How long will it take to recover from colonoscopy?

It will usually only take a few hours to a day to completely recover after the process. However, the patients will need to follow medical advice like:

• Not consuming alcohol for a minimum of 24 hours post procedure
• Adequate rest for a day or two
• Resuming normal diet
• Drinking an adequate quantity of water
• Avoiding heavy work for a day or two
• Taking medications (if any have been prescribed by the doctor)

What do I need to do before a colonoscopy?

You will need to inform your doctor if you suffer from medical conditions like lung issues, allergies, heart conditions, blood clotting issues, pregnancy, diabetes, etc. Additionally, you may also want to tell your doctor of the medications that you are currently taking.

Sometimes, your doctor will prescribe you a few days’ course of antibiotics if you have conditions like:

• Congenital heart disease,
• Having an artificial heart valve

What happens after a colonoscopy?

After the process, you will need to stay in the recovery room for an hour or so for observation. Once the doctor feels it safe, you may be discharged and asked to resume your normal diet.

However, the doctor may advise you to rest for a day or so and avoid doing heavy work. Additionally, your doctor may also ask you to avoid certain blood-thinning medications temporarily.

Is colonoscopy safe?

Yes, colonoscopies are done every day and are considered safe.

How long will it be before my next bowel movement?

It could take a couple of days before your next bowel movement. This is because the colon has been completely emptied.

What can you eat and drink a few days before a colonoscopy?

Your medical practitioner may ask you to avoid certain foods a few days before the procedure. It is usually suggested to drink good quantities of clear liquid like water, apple juice, clear broths, to prevent dehydration.

You will, however, not be allowed to eat or drink anything for at least four hours before the process.

Colonoscopy at Gleneagles Hospital

Gleneagles Hospital provides standard colonoscopy and endoscopy.

A customised treatment plan is used to ensure that the needs of every patient are met. Your attending gastroenterologist will facilitate your care and guide you through the processes.

With advanced diagnosis tools, the use of modern equipment, and tailored treatment plans, Gleneagles Hospitals aim for the best outcome, so you can recover from the procedure with fewer side effects.

If you experience unexplained diarrhoea, severe abdominal pain, blood in stool, fever, constipation, or other symptoms of colon-related issues, make an appointment with a gastroenterogist at Gleneagles Hospital.

References

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2. Colonoscopy, Available at: https://www.mayoclinic.org/tests-procedures/colonoscopy/about/pac-20393569 [Accessed on: 23 March 2022]
3. Colonoscopy, screening, procedure details and preparation, Available at: https://my.clevelandclinic.org/health/diagnostics/4949-colonoscopy [Accessed on: 23 March 2022]
4. Colonoscopy, Available at: https://www.medicalnewstoday.com/articles/colonoscopy [Accessed on: 23 March 2022]
5. Colonoscopy, Available at: https://www.healthline.com/health/colonoscopy [Accessed on: 23 March 2022]
6. Colonoscopy Procedure and Preparation, Available at: https://www.medicinenet.com/colonoscopy/article.htm [Accessed on: 23 March 2022]