Understanding colonoscopy

A colonoscopy is one of those health screenings you may have heard of, but you aren’t entirely sure of the facts. Dr Peter Barrow, a gastroenterologist at Wits Donald Gordon Medical Centre, answers common questions. For starters, does it hurt? “A well-performed colonoscopy isn’t normally painful, but it is uncomfortable,” he says. The colonoscopy itself usually takes 30-45 minutes. However, there will also be an assessment beforehand, you’ll have a drip inserted for sedation and you need about 30 minutes to recover from the sedation afterwards before a debrief with the doctor. Dr Barrow recommends allowing up to three hours from arrival to departure.

The process

Prep work. The process actually begins before you even arrive at the doctor’s rooms. “The patient needs to ‘clean out’ their colon so the endoscopist [person doing the scope] can see the entire colon. In fact, good bowel prep is probably the most important part of a colonoscopy, because if you are only 80% clean, the doctor can only see 80% of your colon, which means small polyps could be missed in the other 20%.”

Sedation. “A colonoscopy is not an operation and doesn’t normally require anaesthesia. However, it is uncomfortable, so it’s done under sedation – often with the help of an anaesthetist. Sedation is like a light sleep.”

Examination. A scope is inserted into your colon, which also blows air to inflate it so the endoscopist can see the entire colon. “If you have symptoms, the doctor is looking for a possible cause of your symptoms,” says Dr Barrow. “However, the main reason for screening colonoscopy is to look for polyps – growths in the colon that, if left, can turn into cancer. If you remove polyps, you can prevent them from turning into cancer.” Any polyps found will usually be removed on the spot – a procedure called a polypectomy.

Post-exam. “You may feel a little bloated and windy because of the air the endoscopist has used to ‘inflate’ your colon. This normally passes quite quickly, and most patients are back to normal within half-an-hour after the scope.”

Note: Don’t make important decisions or operate heavy machinery for eight to 12 hours after sedation. This includes driving a car, so arrange for someone to fetch you.

Low-risk procedure

“If the colon is normal, a colonoscopy is one of the safest medical procedures you can undergo,” says Dr Barrow. “The biggest risk is if there is an underlying problem. There’s a small risk of making a hole in your colon when removing a polyp. However, the risk of leaving the polyp is far greater than the risk of cutting it out.”

Who should have a colonoscopy?

The South African Gastroenterology Society (SAGES) recommends everyone over age 50 should be considered for colon cancer screening, either via stool sample or a screening colonoscopy (in the US, the recommended age to start screening dropped to 45 in 2021). “However, it’s important to understand that screening is for people without symptoms,” says Dr Barrow. “Anybody of any age with rectal bleeding, recent-onset change of bowel habits – especially if they have a family history of colon cancer – or unexplained loss of weight should consider a colonoscopy.”

How often do I need this procedure?

If the quality of your colonoscopy was good and the doctor didn’t find anything concerning, you only need to go again in 10 years’ time. However, “this recommendation changes if you have strong family history of early-onset colon cancer or if polyps were found at the time of the screening colonoscopy,” cautions Dr Barrow. “Then your endoscopist may recommend more frequent check-ups, every three to five years.”

How to prepare for your colonoscopy

“A colonoscopy is really only as good as the bowel prep, so it’s important to follow your doctor’s instructions,” insists Dr Barrow. In general:

• Avoid seeds, nuts, pips and skins of fruit and vegetables for a day or two before the scope.
• The day before, consume only clear fluids instead of solid food. “Clear fluids may include water, jelly, juice (apple or white grape), or clear soups or broths (bone broth or vegetable stock dissolved in water).” Avoid dairy, although you can have black tea or coffee.
• “You also need to take some sort of medication to ‘purge’ the colon. There are various options, but my preferred bowel prep is a polyethylene glycol electrolyte solution, which really flushes out the system,” says Dr Barrow.

Colonoscopy is one of the procedures offered on Mediclinic’s Fixed Fees programme. Visit the Fixed Fees portal on the Mediclinic website for more information and pricing.