Colorectal cancer is the number 1 cancer in Singapore. "Colonoscopy Singapore" is also one of the most-searched terms locally, with 2000 searches each month.
The recent change in screening guidelines by the American Cancer Society to recommend the commencement of colorectal cancer screening at age 45 for people at average risk of colorectal cancer (as compared to age 50 previously) has raised concerns about the rising incidence of colorectal cancer around the world.
This rising trend has been observed in Singapore too, with worrying statistics that up to 1 in 5 Singaporeans diagnosed with colorectal cancer is less than 55 years old. 60% of patients also present in advanced stages of the disease, so one can appreciate the importance of early detection of pre-cancerous polyps or cancers - this allows for less invasive treatment options and better outcomes.
Below I attempt to explain everything you need to know about getting a colonoscopy in Singapore, and address some of the most common concerns that my patients have about colonoscopies.
“I noticed blood in my stools. Do I have cancer?”
Seeing blood in your stools often sets off alarm bells as it can be quite shocking, especially if the bleeding appears profuse with blood staining the entire toilet bowl.
While it should rightly set you on an early course of self-discovery to investigate the source of bleeding, such bleeding is often not due to cancer, but other causes such as:
- Anal fissures or
- Diverticular disease
Do note that these can also have serious health implications if left untreated, so it's important for you to see your doctor if you notice any bleeding!
Cancers often bleed inconsistently and insidiously. In some cases, it can lead to life threatening anemia before you even notice blood in their stools. This is why the stool occult blood test is commonly carried out as a screening tool in Singapore. It enables doctors to test for blood that's invisible to the naked eye.
Commonly, we investigate a patient for bleeding from piles (hemorrhoids), only to discover a cancer in the colon (which had no symptoms).
This explains why your doctor might advise you for a colonoscopy even if it seems like the source of the bleeding is likely to be from your anus (especially in the presence of risk factors or being in the screening age group).
“My doctor told me I need to have a colonoscopy. Does it mean I have colon cancer?”
No, it does not mean you have colon cancer.
A colonoscopy is just a way to look inside your colon. It enables us to:
- Investigate the cause of your bowel symptoms
- Screen for colorectal cancer
The colonoscopy procedure involves the use of a flexible camera that's inserted into your colon via your anus.
While colonoscopies sound scary and unpleasant, it's often performed under sedation, which reduces any discomfort you might experience. Often, our patients do not recall the entire procedure.
At what age should you start having colonoscopy screening tests?
The latest American Cancer Society Guidelines suggest commencement of screening at the age of 45 years old for average risk individuals.
In Singapore, we commence screening:
- When you are 50 years old
- Before you are 50 years old if you have an increased risk (eg. a family history of colorectal cancer or related cancers).
It's important to emphasize that these guidelines only apply if you DO NOT have symptoms.
If you have symptoms, e.g. change in your bowel habits or blood in your stools, you need to be investigated earlier as the cause of your symptoms, whether it is cancer or not, needs to be identified and treated.
Remember, a colonoscopy is just a way to look inside your colon, and in some instances treat the problem. It should NOT be associated with looking for cancers only.
What can your doctor do during a colonoscopy?
The purpose of a colonoscopy can be divided into:
- Screening and diagnostic
- Therapeutic purposes
1. Screening and diagnostic for patients who have no symptoms
In a screening colonoscopy we will be looking out for:
- Other incidental findings like diverticulosis
Polyps will be removed (polypectomy) for histological confirmation and prevention of possible progression to cancer, while large tumours will be biopsied for histological confirmation of their nature.
2. Therapeutic purposes for patients with symptoms
In a diagnostic or therapeutic colonoscopy, on top of looking for the findings above (and more), we will also be looking for the source of the patient’s symptoms and treating it if possible.
For example, in patients who have profuse bleeding from diverticular disease of the colon, a colonoscopy can be attempted to stop the bleeding through a variety of ways. Any suspicious-looking polyps can also be biopsied.
Finally. Colonoscopies are also a very good modality to investigate patients with suspected inflammatory bowel disease and infective colitis, which has not been responding to medical therapy.
How much does a colonoscopy cost in Singapore?
The cost of a colonoscopy varies widely. Even different departments within the same public hospital have varying prices due to multiple cost factors.
On average however, a colonoscopy in Singapore can cost about $1,100 to $2,500 at public and private hospitals for non-subsidized patients.
The cost of a colonoscopy in Singapore for subsidized patients can range from $300 - $ 850 at public hospitals.
These prices are also easily obtainable when you call or send in an enquiry to the centres that you are interested in having your colonoscopy at.
It's important to note that the price quoted can increase if a biopsy or polypectomy is performed. This is because there will be an additional charge for:
- The procedure itself
- The instruments used for the procedure
- The pathology laboratory cost
Can you claim Medisave for getting a colonoscopy in Singapore?
The Medisave claim amount for a colonoscopy is standardized at $950 regardless of whether you have your colonoscopy in Private or Public.
The tricky question is whether your insurance covers the procedure. This is a question I get everyday and unfortunately, the answer lies with you.
Whether your insurance covers the procedure depends on whether there are any restrictions placed on your purchased medical coverage.
Do check with your agent if the procedure is covered by the plan that you purchased, and if there are any restrictions on the specialists that you can see for your colonoscopy.
What’s the difference between private and public for your colonoscopy in Singapore?
The key differences between having your colonoscopy done in a private centre instead of a public hospital are:
- The levels of dedicated specialist care
- The service standards
Public hospitals are important training institutions, which is essential to our healthcare ecosystem in Singapore. As such, patients in public hospitals are placed under the care of a team of doctors, which is supervised by a specialist. This allows our specialists to cope with the high volume of patients seen in public hospitals.
Consequently, there are sometimes increased waiting times for:
- The earliest appointment date
- Seeing the doctor on the day of the consultation itself
- The post-endoscopy follow-up appointments
These waiting periods are often stressful and anxiety-provoking.
It's important that I stress at this juncture that colonoscopy standards are very tightly audited throughout our public institutions. However, for patients who prefer to have more dedicated time spent with your specialist, or more flexibility with arranging your consultation and colonoscopy appointments, a private centre might be a good alternative option.
The range of prices for colonoscopies in both the private and public hospitals vary widely between private clinics and class status in restructured hospitals. Please do your research before deciding on where to get your colonoscopy performed at.
What's the most common misconception that Singaporeans have about colonoscopies?
My patients often ask me if choosing a different investigation will allow them to avoid drinking the bowel preparation fluid or avoid having the discomfort of air being pumped in through their anus.
However, these measures are still necessary regardless of the chosen investigation in order to:
- Cleanse the bowel of stools
- Inflate a collapsed colon so that we can survey the colon accurately
Remember, any investigation is only as accurate as your bowel preparation. The cleaner the preparation, the more accurate the investigation is.
“Colonoscopies sound scary. Do I have any other alternatives?”
Yes, there are alternatives to a colonoscopy, depending on your symptoms. However, each alternate modality has its own benefits and drawbacks.
It's important to understand the pros and cons of each, so that you can appreciate the possible differences in investigative outcomes.
The key benefit of a colonoscopy is:
- The direct visualization of your colon through the lens of the camera
- The ability of the colonoscopy to perform procedures such as biopsies and polypectomies, which not only provides histological confirmation of the visualized problem, but also allows us to remove pre-cancerous polyps
However, as with all invasive procedures, there are risks involved. These are mainly that of:
- Bleeding from the colon
- Perforation of the colon (which occurs in 1 in 1000 patients)
Such complications might need surgical intervention to treat.
When is a CT Colonography offered instead of a colonoscopy?
A Computed Tomography Colonography is offered when:
- You are concerned about the possible complications of a colonoscopy
- You are not suitable for a colonoscopy (eg. kinks in the colon preventing the passage of the colonoscope)
- You are unable to tolerate the procedure despite sedation
CT Colonography involves the use of a CT Scan to create a 3D image of the colon after pumping air and fluid in.
So yes, you'll still need to drink your bowel preparation/oral contrast, and yes you'll still have an anal tube inserted to pump air in.
What's the disadvantage of a CT Colonography?
The downside of a CT Colonography is that:
- It's unable to directly visualize the lesion through a lens (eg. a piece of stool stuck to the wall of the colon can be mistaken for a polyp)
- It's unable to biopsy the lesion even if it detects one
Hence, if your CT Colonography picks up a problem, you'll still need to go for a colonoscopy to:
- Visually confirm that the lesion is truly present
- Biopsy the lesion to confirm its nature histologically
Other issues with a CT Colonography include the use of radiation to generate the images, and the use of intravenous contrast agents (which can affect kidney function) to provide a sharper image.
Why is CT Colonography still used if it's such a “poor” alternative to a colonoscopy?
Well, certain groups of patients face a much higher risk than average when undergoing colonoscopy.
- Patients whose medical conditions necessitate the use of strong blood thinners, which increases the risk of life threatening bleeding from a colonoscopy, or
- Patients who are too medically frail to undergo a colonoscopy
In these patients, it would be a viable alternative to undergo a non-invasive procedure first to allow the patient and his medical team to decide if the risk of undergoing a subsequent colonoscopy is worth it.
If the CT Colonography shows a serious pathology in the colon, which might affect their prognosis, then the risk of proceeding with a colonoscopy (and the subsequent treatment plan) might be balanced by the potential benefits.
When is a barium enema offered instead of a colonoscopy?
Barium Enemas are seldom performed nowadays with the advent of the CT Colonography.
In essence, a Barium Enema performs the same function as the CT Colonography, but uses an X-Ray machine instead of a CT Scanner.
How should you prepare for your colonoscopy?
Different doctors have unique concoctions with regards to their preferred bowel preparation regime.
I continue to learn about new “recipes” every now and then when I converse with my colleagues from different departments and hospitals in Singapore.
These recipes vary according to:
- The type of laxatives used
- The number of laxatives used
- The timings that they are administered
There are many reasons for these variations, ranging from the endoscopist’s experience, to what is available in the centre that you are getting your colonoscopy performed at.
In general, the preparation involves 3 phases:
1. Pre-preparation phase
Ensure that you have informed your doctor if you are taking any blood thinning medications eg. Warfarin / Aspirin / Plavix / Rivaroxaban etc, as these might cause bleeding during the colonoscopy.
If you are not sure, please run through your medications with your endoscopist prior to the colonoscopy.
Another measure proposed (but not absolutely necessary) is to keep to a low fibre diet for 3 to 5 days prior to your colonoscopy.
This allows a better laxative effect by reducing the fibrous residue load in the colon prior to bowel preparation.
2. Preparation phase
Follow the preparation regime prescribed by your doctor. The regime varies with:
- The type of laxative used
- The timing of your colonoscopy
It's crucial that you adhere to the prescribed regime and inform your doctor if you do not have clear bowel effluent (your stools after finishing your bowel prep agent) prior to your scope.
If your bowel is still unclean after the bowel prep, it's much better to delay your scope and clear your bowels thoroughly first instead of proceeding with the scope.
Having a scope anyway will be a complete waste of effort and money as your doctor will not be able to visualize your colon well.
3. Pre-scope phase
In general, you should avoid drinking or eating after your bowel preparation, and before your colonoscopy.
This is because it might contribute to new effluent that coats the colon (eg. coffee) or present as an aspiration risk should you vomit while sedated.
Again, check with your endoscopist on the detailed instructions as they vary depending on the centre that you are getting your scope done.
Who does colonoscopies in Singapore?
In Singapore, only accredited endoscopists who are specialists in General Surgery or Gastroenterology are allowed to perform colonoscopies.
Endoscopy accreditation standards are identical across the board, regardless of specialty.
The specialists who perform colonoscopies most commonly in Singapore are:
- General surgeons
- Colorectal surgeons
What happens during your colonoscopy in Singapore?
On arrival at your endoscopy centre, a pre-procedure safety check will be performed to ensure that you are fit to proceed with the scope, and that the bowel preparation regime was adhered to.
After which, you will be dressed in the endoscopy gown and brought to the endoscopy suite for your procedure.
Your endoscopist will administer the mild sedative after you have settled into the correct position on the bed.
The actual procedure will take approximately 15 minutes, depending on:
- Whether there are any findings noted on the scope that needs intervention
- Your cooperation with the procedure
Even though you'll likely sleep through the entire procedure and have no recollection, your body is actually reacting to us during the endoscopy. Occasionally, patients can resist us to the point that the scope has to be aborted.
After the scope has been completed, you will rest in the recovery area until you are fit enough to be discharged from the centre safely.
The effects after sedation are variable and can last for a few hours, hence you are strongly advised to have someone accompany you home. You also must NOT drive / operate machinery after your scope.
How painful is the colonoscopy procedure?
A colonoscopy is uncomfortable mainly due to the distension of the colon.
This results from the air pumped into the colon, as well as the sensation of the colonoscope inside the intestines.
However, as most patients undergo the procedure with sedation, you will likely sleep through the whole procedure without much recollection.
Most patients do not experience any discomfort after the procedure once they have passed the air out.
"Yes, a colonoscopy CAN be done poorly or give inaccurate results!"
No medical investigation is 100% accurate. It's thus important to know how you can help improve the accuracy of the investigations that you are undergoing. This enables you to buy yourself a peace of mind that the results of the test can be trusted.
The sensitivity of a colonoscopy largely depends on how clean the bowel is after the preparation.
As the suction channel of the colonoscope is very fine, fibrous debris and solid material cannot be sucked out with the colonoscope.
Consequently, it's imperative that strict adherence to the bowel preparation regime is followed so that we can get the best result possible from the scope.
Even with the best preparation, a colonoscopy is only 95 – 98% accurate. This is because small lesions can hide behind the folds of the colon (called haustra), as well as behind kinks and corners in the intestine that avoids detection by the lens’ field of vision.
I hope this article has helped to dispel some myths and unwarranted fears about undergoing a colonoscopy.
With an abundance of endoscopy facilities available around the island now (both public and private), speak to your regular doctor about screening for colorectal cancer. Screening save lives.
Dr Jason Lim is a qualified specialist in General Surgery and Colorectal Surgery. His subspecialty clinical interests includes the treatment of complex anal conditions e.g. perianal fistula, functional bowel problems including irritable bowel syndrome, intractable constipation and bowel incontinence. He also published the first research paper on the prevalence of faecal incontinence in Singapore.
- Wadhwa, V., Issa, D., Garg, S. et al, Similar risk of cardiopulmonary adverse events between propofol and traditional anesthesia for gastrointestinal endoscopy: a systematic review and meta-analysis. Clin Gastroenterol Hepatol. 2016;
- Colonoscopy. American Society of Colon and Rectal Surgeons.