If you have an appointment for a colonoscopy exam there will be some preparation the day before, which your doctor will inform you of in advance. It is important to follow the guidelines as the preparation is required to ensure the results will be as accurate as possible. Having a basic understanding of the colonoscopy procedure also means you are generally prepared for the exam, so you know what to expect.

Colonoscopy prep – the week before

A week or so before the examination, you may be required to adjust any medications you are taking, particularly those for high blood pressure or diabetes, or any iron supplements.

It is important to speak to your doctor about in advance so you can be guided on when to adjust, and how to adjust.

Also, blood-thinning medication, or medication used to prevent blood clots or strokes may also need to be avoided temporarily, such as aspirin, warfarin, dabigatran or rivaroxaban, clopidogrel. Whatever medication you are taking discuss it with your doctor.

Colonoscopy prep – the day before

It is important for the colon to be completely empty when the colonoscopy takes place. This is because it gives the doctor much better vision without any residue.

The day before your exam you will be advised to do the following:

Colonoscopy Diet

It is usual for your doctor to recommend that you don’t eat solid foods the day before. Clear liquids are suggested so that the test doesn’t confuse any coloured liquid left in your body with blood. Red liquid should particularly be avoided for that reason.

Sometimes it is recommended not to drink anything the night before the exam, but your doctor will give you specific guidelines according to their experience.

Take a laxative

A laxative will help to ensure that your colon is completely empty.  A tablet or liquid laxative will need to be taken the night before and also often the morning of the colonoscopy exam as well. The laxative is often quite strong so as to maximise the chances of a successful procedure.

Use an enema

Some people are also advised to use an enema kit, which clears the colon by inserting a liquid into the bowel through the rectum. There is also sometimes the option for a nurse to administer the enema for you, prior to the colonoscopy.

However, many patients are more comfortable to take the laxative in their own home the night before and come to the colonoscopy outpatient clinic prepared.

Colonoscopy procedure – what to expect on the day

It always helps to know what to expect from a medical examination in advance so you can also prepare yourself mentally.

The colonoscopy is a routine procedure and whilst it isn’t the most pleasant of tests, it is highly accurate for inspecting the bowel for signs of cancer and other gastroenterological conditions.

GI Doctors ensure that you will be made as comfortable as possible before, during and after your examination.

These is broadly what to expect from the colonoscopy:

Risk assessment

Whilst the risks associated with a colonoscopy are minimal, there are always some risks. Some time will be spent in advance of the procedure to remind you of these and ensure you don’t have any more questions. A consent form will need to be signed to confirm that you understand the risks involved and want to proceed with the exam.


A mild sedative is usually all that is needed for a colonoscopy, however if you are particularly anxious then it is possible to use a general anaesthetic, but this is the exception rather than the rule.

The sedative will help minimise discomfort during the procedure.


Usually the doctor will inspect the rectum initially with a gloved finger. Then they will request that you lie on your side with your knees to your chest.

The colonoscope, which is a thin, flexible tube housing a camera and bright light is inserted into the rectum. Air can be pumped into the colon for ease of movement, creating space for the colonoscope to travel.

The colonoscope will work it’s way all the way up to the top of the colon and back down, while the doctor views images on the screen. It is possible for you to also look, if you want to, or not – the choice is yours.

If bowel polyps are found during the colonoscopy then the colonoscope has a tool to snip these off, after which they can be examined in a lab to see if they were cancerous.

The duration of the colonoscopy usually takes 20-30 minutes but it may be up to an hour, depending on if your colon has any difficult twists and turns to navigate.

After the test

After the procedure you will be able to go home, but only after about an hour, when the sedative has worn off. Driving or working that day is not allowed, as the sedative will take up to 24 hours to wear off completely, so you will need someone to drive you home.

The next day you may experience some blood when you first go to the toilet. This is normal, however excessive blood, or continued bleeding could be a cause for concern so you need to visit a doctor.

Working with a specialist will give you peace of mind that your colonoscopy examination is performed accurately and with minimal discomfort.