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Day-case Colonoscopy

1. Why do you need to get a colonoscopy?


Colorectal cancer as the most common cancer in Hong Kong


The Department of Health (DH) announced in August 2018 that colorectal cancer ranked the most common cancer locally. In 2016, colorectal cancer resulted in 2 089 deaths, accounting for 14.7 per cent of all cancer deaths.


There has been substantial proof around the world that colorectal cancer screening can lower the incidence rate of the disease. In the US, asymptomatic individuals regularly undergo screening for colorectal cancer from the age of 50.


Colorectal cancer prevention with colonoscopy



The colorectal adenoma-carcinoma sequence suggests that a clump of cells form the adenomas polyps that attach to surface of the colon’s mucous membrane, and the adenomas polyps become cancerous. It is believed that environmental factors such as food can alter the way molecules bind to DNA. It takes about 10 years for an adenoma  polyp to turn into cancer. Over 70 percent of colorectal cancers begin as a benign polyp. Removing the adenomas polyps can help prevent colorectal cancer from developing.

The common types of polyps include hyperplastic polyps, adenomas polyps, sessile serrated adenoma, Peutz-Jehger polyps, and juvenile polyps. If the polyps are not removed, they could turn into colorectal cancer. 


A young-shift in colon cancer in Hong Kong

In the latest research (2018) by The Chinese University of Hong Kong revealed, there is a global trend towards a “young-shift” in colorectal cancer. Obesity is a growing global issue, especially among the younger population in developed countries. It is linked to the change in gut microbiota. We believe that could be one of the factors in why more and more younger individuals are suffering from colorectal cancer. The youngest age of colorectal cancer diagnosed in our Centre was 23 years old.




Patients may sleep through a colonoscopy with sedation and will not feel pain. Colonoscopy is the endoscopic examination of the inner lining of the large bowel (colon) with a flexible endoscope, by passing through the anus to the lower bowel to examine if there is any inflammation, polyp or tumour. Colonoscopy can remove polyps or biopsies when any suspicious found. After its removal, the biopsy specimen will be sent to the laboratory for testing.

Colonoscopy offers the best prevention for colorectal cancer. However, the polyps can grow back after they have been removed once. Regular screening test, such as a colonoscopy, can find colon polyps and have them removed safely.


2. Medical Statistics Analysis Issued by The Specialists


On 13 June 2017, The Specialists has organized a Press Conference on Clinical Performance of Day Colonoscopy with The Hong Kong Polytechnic University to release and analyse the clinical performance statistics of the past 10 years (2006–2015) by collecting a total of 21 004 colonoscopy reports. Among which, there are 689 cancer cases and 30 867 polyps removed in total.


Some highlights in findings are listed in the table below.


In this survey, the findings are mainly based on the medical knowledge and professional judgment The Specialists. The Centre for Social Policy Studies (CSPS) of Department of Applied Social Sciences, The Hong Kong Polytechnic University was responsible for inputting data and processing the calculation. The data was, them, sent back to The Specialists for medical analysis and interpretation.


3. Who should have colonoscopy?

  • start after the age of 50
  • have a family history of colon cancer
  • have per rectal bleeding
  • experience bloating
  • experience unexplained abdominal pain
  • have suspected colonic polyps
  • have inflammatory bowel disease


4. How to prepare for the procedure?


Prior to the procedure, patients should:


  • A pre-consultation is required during which the doctor is able to determine whether the patient's physical condition is suitable for endoscopy or anaesthesia procedures. And doctor will let the patient know the risks associated with the examination.
  • Stop taking iron supplement for 3 days before the procedure. Patients who are taking wafarin and aspirin should inform the doctor in advance. In some cases, doctor may ask the patient to stop taking the medication prior to the examination.
  • Stop ingesting high fibre diet/drink including vegetables, fruit, wheat, mushrooms and cereals three (3) days before the procedure. Patients can eat starchy, protein and fatty foods.
  • Only take clear liquid the day before the procedure. Patients can have fish congee and minced meat congee.
  • Patients should take the laxative prescribed by the doctor on the day before the test/or in the morning of the test. (Patients are not recommended to buy the laxative by themselves). Before drinking laxatives, patients can prepare 2 litres of electrolyte water, cleansing wipes for skin and petrolatum.
  • Do not eat anything for 6 hours before the procedure.
  • Do not eat and drink anything for 2 hours before the procedure.
  • Doctor will have a brief consultation with the patient to explain the procedure and the risks involved. A consent form will then be signed by the patient.
  • Remove the denture, accessories and metallic objects.
  • If the patient suspects that she is pregnant, she should be sure to let the doctor know.


5. What happens during the colonoscopy?



The endoscope can be passed into the colon

If polyps are found, doctor will remove them or take biopsies for analysis

CO2 will be pumped into the colon during colonoscopy and can reduce abdominal bloating as a result

The entire procedure should take around 30 minutes


*According to the patient's condition, the method of anesthesia is determined by doctor.


  1. The examination will be performed only when the patient is asleep after intravenous sedation or monitored anaesthesia care administered by anaesthesiologist, to avoid any discomfort. The anaesthesiologists participate in providing anaesthetic opinions to patients prior to the endoscopy. During the procedure, they will constantly monitor the stability of vital signs including pulse, breathe, blood pressure, to preserve the vitality of important organ functions. Monitored anaesthesia care is a special alternative for patients that require maximum comfort and safety. 

  2. Doctor will apply some lubricant to the anal region. A flexible colonoscope with a diameter of around 1.5cm will then be introduced by the endoscopist through the anus to examine the colon.

  3. The colonoscopy allows the doctor to take a biopsy or remove polyps during the procedure.

  4. During the endoscopy process, a small amount of air insufflation is applied to visualize the colon images. It is normal to have cramps and a feeling of wanting to go to the toilet. An alternative gas that can be pumped into the colon during colonoscopy is carbon dioxide (CO2). Unlike air, CO2 is very rapidly reabsorbed into the body from the colon, about 150 times faster than air.

  5. The procedure will be completed in 30 minutes.



6. After the procedure


  • After the patient completes the procedure, he/she will be sent to the recovery area. We have a dedicated nurse take good care of the patient and carefully monitor the patient's vital signs. After the patient wakes up, he/she will be transferred to the private resting room.
  • In the private resting room, in addition to the vital signs monitor connected with the central system, we have an alarm clock, lifesaving alarm, walkie-talkie and other medical equipment. There are also entertainment facilities such as sofas, TV set and magazines. The room is prepared after the procedure to give patient time to wear off the sedation. Family members can accompany during the time.
  • As patient is sedated, he/she should be accompanied by at least a friend or a family member aged above 18.
  • The sedation and the anaesthetics may temporarily affect one's co-ordination and reasoning skills, therefore, avoid driving, drinking alcohol, making any important decisions or signing legal documents in 24 hours after the procedure.
  • Patients can resume normal diet after colonoscopy. However, if the patient has undergone a polypectomy, he/she will be asked to fasten certain types of vegetables and fruits within 10 days of the examination.
  • If the patient has undergone polypectomy or extraction of biopsies during the procedure, he/she will be strongly advised to stay in Hong Kong for 10 days after surgery. If the patient cannot promise to stay in Hong Kong for 10 days after surgery, please inform the doctor before the test.


7. Devices to improve the colonoscopy output


Endoscopy Rooms


Both the endoscopy rooms and cleansing room are maintained at negative pressure. The cleansing room was constructed with the advice of our contractor Olympus, with the new models of endoscope reprocessors being used. To prevent cross infection, our endoscopic apparatus such as the hot biopsy forceps and the polypectomy snares are all disposable.
To provide an optimal medical service, we have lately introduced Olympus EVIS X1 endoscopic series which has already been in operation since November 2020. As the latest innovation, EVIS X1 uses the artificial intelligence (AI) to detect gastrointestinal disorders. 

New technologies include 5 LED Spectrum, Texture and Colour Enhancement Imaging (TXI), Extended Depth of Field (EDOF) with a normal focus mode (3-100mm), a near focus mode (1.5-5.5mm), wide-angle field of view, Red Dichromatic Imaging (RDI), as well as the Narrow Band Imaging (NBI). The advanced system delivers more refined image quality for better diagnosis and effective treatment and is optimized for the detection of adenomas polyps and early cancer. 


Available instruments and techniques


To prevent cross infection, our endoscopic apparatus such as the hot biopsy forceps and the polypectomy snares are all disposable. Furthermore, we provide the Narrow Band Imaging (NBI) technology that can offer twice the viewable distance than the previous type, projecting a more clear-cut observation for any lesion with abnormal blood vessels and mucosa.


During colonoscopy, carbon dioxide (CO2) is to insufflate the colon as CO2 absorbs considerably faster than air. We introduce the Olympus UCR CO2 Regulation Unit that provides intra-luminal insufflation using carbon dioxide to minimize bowel distension, reduce patient discomfort, and speed up the recovery afterwards.


Advanced apparatus and technologies including endoscopic submucosal dissection (ESD) and auto pressure water jet are also introduced in the centre.



For gastric irrigation, we use sterile medical water from a well-known medical brand.


8. Medical suppor


Immediate treatment for colonoscopic perforation and bleeding of the colon

Equipment for resuscitaion in the ecovery area

24-hr emergency telephone hotline



  • If perforation or bleeding happens after the procedure, patients may receive follow up service gratis when necessary to ensure you get the most attentive post-operative care.
  • The certified resuscitation area is equipped with all sorts of airway and intubation instruments including the endoscopic guided intubation facility, ventilator, oxygen generating machine, lifesaving medications and the cardioverter. Moreover, all our medical staff receives regular training on resuscitation to ensure patients can get the medical assistance in case of any emergency timely and properly.
  • If perforation or bleeding happens after the procedure, patients may receive follow up service gratis when necessary to ensure our patients get the most attentive post-operative care.


9. Conclusions


Existing medical data prove that colonoscopy can effectively reduce the incidence and mortality of colorectal cancer. Citizens are recommended to have colorectal screening routinely to spot the colorectal cancer at the early stage and receive the appropriate treatment.





(Narrow Band Imaging (NBI) included)

Total number of polyp and/or biopsy

Package Price






10‭ ‬or above


Types of Anaesthesia

Monitored Anaesthesia Care‭ (‬M.A.C.‭)‬

+ $2,200


The Package Price above covers Surgeon's Fee, Instrument Fee, Pathology Fee, CO2 Fee, Operation Theatre Fee, an Endoscopy Report, Post-operative Medication Fee, Post-operative Report Interpretation and other miscellaneous charges during the procedure.


Colonoscopy and Gastroscopy must be using Monitored Anaesthetic Care (M.A.C.).


The price listed are for reference only. Prices are subject to change without prior notice.