Hi Cai Shum,
A colonoscopy is one of the investigative tools we have to examine the colon, rectum and in some cases the terminal ileum. The alternatives are a computed tomography scan of the colon (also known as a CT Colonography) and a barium enema.
The key benefit of performing a colonoscopy is the ability to directly visualize the colonic lumen through a high definition lens and biopsy the lesion if necessary.
This cannot be done with the other imaging options. The common example is the poorer ability of scans to differentiate small polyps from stool remnants, as well the inability of scans to remove these polyps (polypectomy) should they be present.
This leads to an additional procedure with the additional inconvenience, cost, and effort attached with it.
To find out more about getting a colonscopy in Singapore, you can read my Complete Guide To Colonoscopies In Singapore (2018).
A standard colonoscopy’s sensitivity is in the range of 95 – 98% accurate, while a CT Colonography’s sensitivity can range from 90 – 95%. However, it is imperative to note that the sensitivity and accuracy of either investigation is highly dependent on the quality of the bowel preparation before the procedure. The poorer the bowel preparation, the lower the accuracy.
In general, a colonoscopy is the preferred mode of investigation as it has the benefits of higher accuracy (with the ability to directly visualize and differentiate lesions through the lens) and the ability to remove or biopsy these lesions during the procedure itself. However, it carries a 1 in 1000 risk of bowel perforation from the procedure, as well as the risks of bleeding, which might need major surgery to treat.
As such, for patients who are aversed to the risks of a colonoscopy, or patients who are too frail medically to undergo the procedure, the option of a virtual colonoscopy (aka CT Colonography) or a barium enema will be considered, with the caveat that the patient understands that they have to accept a lower accuracy of the imaging findings, as well as the possible need for a colonoscopy to clarify, confirm and biopsy suspected lesions noted on the imaging tests.
Capsule endoscopy is used for the small intestines and is not considered an alternative to a colonoscopy.
It is not uncommon for doctors to miss polyps during a colonoscopy.
There are no figures locally on how often this happens but these can be due to three main factors:
To find out more about getting a colonoscopy in Singapore, you can read my Complete Guide To Colonoscopies In Singapore (2018).
My advice is to gather direct feedback from trusted friends and relatives who have undergone a successful colonoscopy on whom to consider as your endoscopist. In this era of fake news and social media marketing, it is even more important now to distil reviews accurately.
When you speak to your endoscopist, remember that you are not obliged to undergo the procedure unless you are comfortable with the doctor and accept the risks involved with the procedure.
Finding a good doctor for your colonoscopy in Singapore should not be that complicated!
A colonoscopy carries a 1 in 1000 risk of perforation. Should a perforation occur, it often requires immediate surgery to repair the perforation. In some instances, a stoma is required to allow the damaged colon to heal.
As such, a colonoscopy should not be considered a “simple” or “risk-free” procedure as the consequences of a complication from the scope can be morbid, with the need for multiple surgical procedures to treat.
To understand more about colonoscopy in Singapore, you can refer to The Complete Guide To Colonoscopies In Singapore (2018).
It depends greatly on what bowel preparation regime is used for the colonoscopy. Different centres and endoscopists have their own regimes, which can range from just 3 small cups of laxative fluid, to over 3 Litres of a bowel cleansing agent.
Speak to your endoscopist on their advice regarding mitigating the experience of bowel preparation with respect to the chosen preparation regime.
You can also find out more about colonoscopies in Singapore here.
If you have booked an advanced date for your colonoscopy, it would be ideal to keep to a low fibre diet 3 to 5 days prior to the date of your colonoscopy. This reduces the fibrous debris in the colon and allows a better clean during the bowel preparation.
Furthermore, the remnant stools, if any, would often be liquid, which can be sucked out by the colonoscope itself.
It is important also to be compliant to the prescribed timing and the volume of the bowel preparation to take. If you are unable to finish the preparation, or vomited the preparation out, please inform the staff prior to undergoing the procedure to avoid having a wasted procedure.
Hi Bing Qi,
A colonoscopy often begins with the administration of a mild sedative which renders the patient unconscious or drowsy for the duration of the procedure.
After which, the colonoscope is inserted into the anus, gas is pumped into the colon and the scope is advanced to the caecum. This is done by a series of maneuvers executed by the endoscopist’s right hand which twists, pulls and pushes the scope, while the left hand manipulates the up-down-left-right controls on the scope handle.
This allows the scope to wriggle its way through the bends and corners of the colon.
The patient is often asleep throughout the procedure due to the sedation administered so essentially the patient often has no recollection of the entire procedure.
If a patient chooses to undergo the procedure without sedation, the common sensation will be that of abdominal cramps and bloating due to the air pumped into the colon during the procedure. This can be very uncomfortable.
Hi Hui Yi,
There is actually no recovery period from the scope itself. However, if you had sedation administered during the procedure, you might suffer a loss of memory or experience drowsiness for up to 12 hours after the procedure depending on the dose and type of sedative used.
I would not advise you to return to work, drive, operate machinery or make important life decisions until at least 12 hours after the procedure.
A colonoscope is washed with a special cleaning fluid either manually or by a machine. All channels of the scope are scrubbed and cleaned and frequent audits are mandated where the scopes are cultured to check their level of sterility and to ensure that proper cleaning procedures are adhered to.
If you are above the age of 45, or have a positive family history, it is important to consider a colonoscopy as part of your routine health screening.
This is because colorectal cancer is the number 1 cancer in Singapore and more often than not begins as a polyp. Polyps are small and have no symptoms. The only way to remove polyps is through a colonoscopy.
The detection and removal of polyps would certainly help one determine his risk factor for developing colon cancer (serves as a guide as to how frequent the colon should be checked), as well as prevent the person from actually developing the cancer when the polyp is removed.
It is worth nothing also that majority of colorectal cancers diagnosed after the development of symptoms is often in the advanced stages of disease. Therefore, one should take that into consideration when deciding whether to screen for polyps and cancers prior to the development of symptoms.
If you are still undecided, a faecal occult blood test is an alternative to test for unseen blood in your stools. While it is not foolproof, it serves as a good impetus for one to undergo a colonoscopy as soon as possible if the test if positive.