What is a colonoscopy?

Despite the seemingly unpleasant nature of the procedure, a colonoscopy is safe, painless, and could save your life. During the procedure, a narrow, flexible tube called a colonoscope is inserted into your anus and gently passed through your bowel and small intestine.

A camera attached to the tube enables your gastroenterologist to investigate and diagnose problems with the bowel and colon. Pain medication and a mild sedative help you remain comfortable and relaxed during the procedure. A colonoscopy can take tissue samples, called biopsies, or remove small growths called polyps. The biopsy or polyp can be sent to a lab for testing. A colonoscopy is the most accurate way to detect colorectal cancer and diagnose other conditions like inflammatory bowel disease.

When do I need a colonoscopy?

Investigate symptoms

A colonoscopy is an effective way to determine for the cause of digestive problems, such as change in the bowel habits, persistent abdominal pain and bloating and rectal bleeding. Other reasons include weight loss, iron deficiency, anaemia or having a positive FOBT also need a colonoscopy.


The main purpose for a colonoscopy is to make an accurate diagnosis promptly and allow treatment early. In the setting of multiple gut symptoms or nutritional deficiency as such as iron or vitamin B12, the colonoscopy allows your physician to visual the surface of the small and large intestine for any inflammation and or ulceration which may suggest inflammatory bowel disease. There are situation where the colonoscopy appears normal but the biopsies are needed to ensure diagnosis such as microscopic colitis or collagenous colitis are missed.

In the setting of bowel cancer screening or a positive FOBT (poo test for blood), colonoscopy is there to find the source of bleeding. It may be an early bowel cancer or colonic polyps that can be removed safely to prevent bowel cancer.


Colonoscopy allows your physician to safely remove colonic polyps without a need for bowel surgery. There are situation where bleeding blood vessels are visible and electrical ablation can be done to cauterise the bleeding point.

Preparing for your gastroscopy

Preparing for your gastroscopy

Step 1 – Preparation

Dr Lee will review specific details such as eating, drinking, any current medications, allergies or other medical conditions before your procedure. As a general guide, you need to have an empty stomach so the physician can see clearly, and so you don’t vomit. This typically means not eating or drinking for up to 4 hours before your procedure.

Step 2 – Procedure

A gastroscopy is often a short procedure of 15 minutes. It is normally painless, but very few patients may experience some discomfort. The anaesthetist will see you prior to your procedure where your medical history is reviewed and you will able to ask any question or share any concern that you may have. A small plastic needle called cannula will be inserted into your vein in the arm where sedatives are given. Next, you will be asked to lie on your side, and the anaesthetic agents will be given to help you falling asleep and stay comfortable. the physician will insert the gastroscope into your mouth into your stomach whilst you are asleep and comfortable.

Step 3 – Recovery

Recovery is typically quick. You will wake up in the recovery where the nurses are there to make sure you wake up safely. You will be given a small meal to ensure you are well before discharge home. Dr Lee will catch you before you leave the hospital. You need to arrange for someone to drive you home, and for at least 24 hours, you should avoid alcohol and driving. Dr Lee will advise on any specific recovery details, including your follow-up consultation.

Frequently Asked Questions about Colonoscopies

Are there alternative procedures to a colonoscopy?

There are alternative tests, but they may not be appropriate or provide the accuracy of a colonoscopy. Tests that provide additional information and are sometimes conducted in conjunction with a colonoscopy include:

  • CT colonography – a scan designed to look at the colon.
  • CT scan – a test to look at other parts of the abdomen.
  • Sigmoidoscopy – a procedure like a colonoscopy, except the sigmoidoscope is much shorter.

How long does it take to get results from a colonoscopy?

Dr Lee will discuss his initial observations as soon as you are fully awake. The observations will determine if follow-ups are needed. Dr Lee will discuss with you how long it will take to get test results and arrange another appointment to discuss your diagnosis, treatment options and answer any questions you have. For Dr Lee, it is important that you are fully informed and given time to think about and understand your diagnosis and treatment options before going ahead. You will be given a copy of your colonoscopy report to take home with.

What are the risks of a colonoscopy?

Dr Lee is an experienced physician who will do everything to reduce risks. Complications, though rare, include:

  • Bleeding from where a tissue sample (biopsy), polyp, or other abnormal growth was removed
  • Tearing in the colon or rectum wall
  • Bruising around the spleen
  • A reaction to the sedative medication used during the procedure

Can my doctor perform a colonoscopy?

A colonoscopy can be performed only by a credentialed clinician who meets the requirements of an accepted certification and have completed recent colonoscopy recertification process through the Gastroenterological Society of Australia (GESA). Gastroenterologists perform colonoscopies because of their expertise and qualifications in treating diseases and conditions related to the digestive system and intestines. Gastroenterologists, including Dr Lee, are members of GESA, which promotes the highest standards in research, education, patient care and clinical practice. You will need a referral from a doctor to see a gastroenterologist.

When should I have a colonoscopy?

Many people approach their doctor when they are experiencing symptoms such as frequent stomach pain, passing blood, chronic diarrhoea or constipation and sudden weight loss. To investigate the causes, your doctor will refer you to a gastroenterologist for a colonoscopy. A colonoscopy is often the best way to investigate and diagnose problems with the bowel properly. To fully investigate what’s causing these issues, your GP will need to refer you to a gastroenterologist. A colonoscopy is often the best way to see inside the bowel to learn more about the causes of your symptoms. Additionally, a colonoscopy is part of routine screening and surveillance for colorectal cancer and colonic polyps.


Organise your visit today

For new and ongoing patients, make a booking to speak to Dr Lee about understanding, managing, and treating your gut health issues.