What is Colonoscopy?

Colonoscopy is a test to look at the lining of the gut mainly the large bowel or colon. We use a flexible telescope with a camera, which sends pictures to a screen. It is a very common investigation for children and adults with gut problems. It helps us find out if there is a problem with the gut and sometimes we use it to check if the gut is getting better with treatment.

How is Colonoscopy performed?

While you are asleep, we will pass a flexible telescope up the back passage (anus) and slowly into the rectum and round the colon. We need to see the lining of the bowel clearly so there has to be no poo in the bowel.

Why do I need this procedure?

Where you have symptoms suggesting possible problems in the lower digestive tract, such as abdominal pain, unexplained weight loss, diarrhea or blood in the stool, your doctor may recommend a colonoscopy to:

  • find out if your digestive tract is healthy or diseased
  • screen for ulcers, inflammation of intestine, polyps or cancer in the digestive tract, and where necessary, take small tissue specimen (biopsy) for further investigation
  • carry out treatment (where possible) through the endoscope at the same examination

What does it involve?

Before the procedure, you must not have anything to eat for about six hours before the test. You are allowed to drink water till two hours before the test.
If colonoscopy is recommended, we need to clear the bowel before the procedure. To help the bowel be clean you need to do three things:

  1. Stay in the hospital one day before the test.
  2. For two days before the test you have to eat a special low residue diet that does not leave bits in the bowel. You must also drink plenty of water or juice.
  3. On the day before the test we will ask you to take some laxative medicine. This medicine will make you go for a poo more often and make the poo watery.

It is very important that you take this medicine exactly as told because if your bowel is not clean, the doctors will not be able to do the test.

You will be put into sleep under general anaesthesia or sedation during the procedure.
When you are asleep, a flexible telescope will be passed down up through the anus (colonoscopy). Tissue samples (biopsy) may be taken for examination during the procedure.

What are the precautions for colonoscopy?

Let your doctor know if you or your child are currently taking medications like Warfarin or antiplatelet agents, e.g. Aspirin, as these medications may have to be changed or stopped for one week prior to the procedure. This decision will be made by your doctor.


Colonoscopy is a very safe procedure. Complications are rare.

However, despite the best of intention, sometimes, problems do occur and they include:

  • Tear in the lining of the intestinal wall (surgery may be needed)
  • Bleeding from the procedure (rare complication)
  • Allergic reaction to the medication

What can I expect after the colonoscopy?

When you wake up from the anaesthetic you sometimes have a sore tummy. You can have some food and a drink as soon as you would like some. You will have to wait for three to four hours in the ward. After you have seen the doctor, you can usually go home.

Got more questions? Schedule an appointment today with Dr. Christina Ong.

Seraphinite AcceleratorOptimized by Seraphinite Accelerator
Turns on site high speed to be attractive for people and search engines.