What is a colonoscopy?

Colonoscopy is a procedure used to examine the large bowel. It also allows a variety of therapeutic procedures to be carried out through the instrument. Such procedures will include taking of tissue samples (biopsies), the removal of polyps, dilatation of narrowing and various treatments to arrest certain forms of bleeding from the bowel.

What to bring

  • Wear loose, comfortable clothing.
  • Your Medicare card, Private health fund and pension or Veterans Affairs details if applicable.
  • A current referral from your GP or referring specialist (unless sent through prior).
  • The contact name and telephone number of someone who will take you home.

Special Considerations

As X-Ray screening may be used very uncommonly during the procedure, it is essential for female patients to inform the nursing staff if there is any possibility of pregnancy. X-Rays are harmful to unborn babies. You should also advise the nursing staff if you are sensitive (allergic) to any drug or other substance.

How are you prepared?

(Please see links at the bottom of this page for detailed instructions)

Prior to the colonoscopy examination you will be provided with a preparation kit and detailed instructions on how to prepare. Five days prior to the procedure you will need to follow a low residue diet. The night before or the morning of your procedure (depending on the time you are booked in) you will need to take a special preparation that completely flushes out your bowel and follow a clear fluid diet. This is all detailed in the instructions you will be given. If you have any questions you can look at our 'FAQs' page. If you cannot find the answer you are looking for please feel free to contact us.

You should cease taking Iron tablets, Fish Oil, Ginko, Ginseng, Chamomile, Evening Primrose, Fenugreek, Valerian or fibre supplements (e.g. Metamucil, Normafibre, Psyllium Husks & Normacol) and drugs to stop diarrhoea five days before the procedure. It is preferable that you do not take NSAIDs (e.g. Voltaren, Nurofen, Mobic) for 7 days prior. If you are on these medications, you should discuss the matter with your doctor. You should also inform your doctor if you are taking blood thinning tablets (Warfarin, Plavix, Asasantin) or have any heart valve disease or an implanted pacemaker.

You will be given a sedative before the procedure begins and usually you will not remember anything about the actual examination.


What do we do?

The colonoscope is a long and highly flexible tube about the thickness of the index finger. It is inserted through the rectum into the large bowel and allows inspection of the whole of the large bowel.

Occasionally, narrowings of the bowel or other diseases may prevent the instrument being inserted through the full length of the colon.

As cancer of the large bowel arises in pre-existing polyps, it is advisable that if polyps are found at the time of the examination they should be removed. Most polyps can be burnt off by placing a wire snare around the base and applying an electric current, thus preventing malignant change in that polyp.

How accurate is colonoscopy?


Colonoscopy has been shown to be significantly more accurate than barium enema in the detection of bowel polyps and cancers. A number of recent studies have examined the accuracy of colonoscopy and concluded that where the instrument cannot be passed all the way around the colon, there is a significant risk of missing polyps and cancers in the unexamined portion of the bowel. For this reason, if your Gastroenterologist is unable to pass the instrument the entire length of the colon, you may need a barium enema or virtual colonoscopy, as there is a small risk polyps can be missed.

After your colonoscopy

You will remain in the endoscopy unit for up to 3 hours until the main effects of the sedation wear off and you have had something to eat/drink. You may feel slightly bloated due to the air that has been introduced through the endoscope. This will quickly pass. You should avoid alcohol for 12 hours after your procedure.

  • For legal reasons you must not drive a vehicle or operate machinery for at least 12 hours following intravenous sedation. Failure to do so carries the same implications as drink driving.
  • You must have a responsible adult escort you home (i.e. you should not go to work) and stay with you for 12 hours after the procedure. Also you should not care for dependent persons without responsible help for at least 12 hours after your procedure.
  • You are also advised to be very careful in simple household tasks in the 12 hours after receiving sedation. Your coordination may be impaired for some time and it is important, therefore, not to use sharp knives, risk kitchen burns etc.

If you develop any pain, fever, vomiting or blood loss after the procedure, you should contact your doctor immediately or the hospital where your procedure took place. Alternately, after hours, you can contact our after hours service on 3261 9570.

Air Travel post Colonoscopy

After your procedure you may be unable to travel domestically for two days or travel internationally for two weeks due to risk of bleeding after having polyps removed.

If this is an issue please discuss this with your doctor.

Safety and risks

For inspection of the bowel alone (diagnostic colonoscopy without removal of polyps or other operative measures) complications of colonoscopy are uncommon. Most surveys report complications in less that 1 in 1000 examinations.

Complications which can occur include intolerance of the bowel preparation solution or reactions to sedatives used. For diagnostic examination, perforation or other major complications are extremely rare but if they do occur, may require surgery.

When operations such as the removal of polyps are performed, there is a slightly higher risk of perforation or bleeding from the site where the polyp has been removed. This can include delayed bleeding which can occur two weeks after procedure.

Complications of sedation are uncommon and are usually avoided by administering oxygen or monitoring the pulse oximeter (a device which measures oxygen in the blood). Rarely, however, (particularly in patients with severe cardiac or chest disease), serious sedation reactions can occur.

A number of rare side effects can occur with any medical procedure. If you wish to have full details of RARE complications, you should discuss further with your doctor before the procedure.

In the unlikely event a complication occurs, your doctor will take all due care to ensure your safety. This may include consultation with other specialists (e.g. surgeon) and additional testing (radiology & blood tests) for which there may be additional fees.

Removal of polyps

The majority of bowel cancers arise from benign adenomatous polyps. Some polyps never become cancerous. It is impossible to predict which polyps will progress to cancers and which will remain as benign polyps. For this reason it is advised that all polyps be removed at the time of examination. As it will not be possible to discuss this at the time of your examination, as you will be sedated, please sign the consent form prior to procedure. If you have any queries or reservations about removing polyps, please inform the staff before the procedure. In the unlikely event that a haemorrhage occurs after removing a polyp, blood transfusion or operation may be necessary.


A copy of the results will be sent to your referring doctor and be provided to you on the day of the procedure or within 3 working days. A full report and assessment will be sent to your referring doctor within approximately 3 days. Your treating specialist will contact you if he has any serious concerns or if you require a further appointment with him. Should you have any questions or concerns contact our practice nurse at Digestive Diseases Queensland.

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