How to Prepare for a Colonoscopy: A Step-by-Step Guide
Preparing for a colonoscopy is one of the most important parts of the procedure. A clean bowel allows your doctor to clearly examine the lining of the colon, identify small polyps, diagnose bowel conditions and detect bowel cancer at an early stage. This guide explains why bowel preparation matters, what to expect before your procedure and practical tips to help make the process as smooth as possible. Specific steps and prescription of the laxative will be given to you by your surgeon before your procedure.
Why is preparing for a colonoscopy so important?
It is common to feel somewhat daunted and unenthused before a colonoscopy. Surprisingly, the procedure itself is often the easiest part - it is the bowel preparation beforehand that most people find challenging.
A colonoscopy uses a small camera to examine the inside of your large bowel, and sometimes, the last part of your small bowel (where it joins onto the large bowel). To do this properly, your bowel needs to be completely clean and empty. Even small amounts of stool can hide polyps, inflammation or early cancers, making it more difficult to identify important findings.
In some cases, poor bowel preparation can mean the procedure needs to be repeated.
Although bowel preparation isn't the most enjoyable part of the process, it's one of the most important things you can do to ensure your colonoscopy provides the most accurate results without needing to be repeated.
When should I start preparing?
Your doctor will give you detailed instructions to follow before your procedure. These instructions may vary slightly depending on the bowel preparation you're prescribed and your medical history, so it's important to follow the advice you've been given.
As a general guide, it's helpful to:
A few days before your colonoscopy
Read through your preparation instructions carefully.
Collect your bowel preparation from the pharmacy.
Make sure you have plenty of clear fluids at home.
Arrange for someone to drive you home after your procedure.
The day before
You'll usually be asked to follow a clear fluid diet and begin drinking your bowel preparation solution according to your instructions.
Expect to spend plenty of time near a bathroom once the preparation starts working, so make sure you have access to a toilet you can get to quickly.
On the day
Continue following your fasting instructions exactly as advised. Your healthcare team will let you know when to stop drinking fluids before your procedure.
What can I eat before a colonoscopy?
Your preparation instructions will explain exactly what you can and can't eat.
In the days leading up to your colonoscopy, you may be asked to avoid certain high-fibre foods that are harder to clear from the bowel.
The day before your procedure, you'll usually be restricted to clear fluids such as:
Water
Clear broth
Clear apple juice
Sports drinks
Tea or coffee without milk
Clear jelly (avoid red or purple varieties)
Tips to make bowel preparation easier
Bowel preparation isn't anyone's favourite experience, but a few simple tips can make it much more bearable.
Chill the preparation solution before drinking it.
Drink it through a straw if you find the taste unpleasant.
Stay well hydrated by drinking clear fluids.
Apply a barrier cream around the anus to help prevent irritation.
Stay close to a bathroom once the preparation begins.
Wear comfortable clothing and allow yourself time to rest.
Remember, the preparation is temporary but essential in ensuring your colonoscopy is successful.
What happens during a colonoscopy?
A colonoscopy is performed using a thin, flexible camera called a colonoscope, usually 130-160 cm long and the width of your finger.
Almost all patients receive sedation, meaning they are breathing for themselves (unlike under a general anaesthetic or ‘GA’) but remember very little of the procedure. The examination usually takes around 20 to 45 minutes, although this can vary significantly depending on how difficult the colonoscopy is, and whether polyps need to be removed or biopsies taken.
During the procedure, your doctor carefully examines the lining of the bowel for polyps, inflammation, bleeding or other abnormalities. Most polyps can be removed during the procedure, and any unusual parts of the colon, such as inflammation or masses, will be biopsied at the same time. Because of this, it is important to tell your doctor if you take blood thinners.
What should I expect afterwards?
After your colonoscopy, you'll wake up in the recovery bay where you will spend a short period as the sedation wears off.
It's normal to experience:
Mild bloating
Wind
Mild abdominal discomfort
Almost all patients are able to return home the same day, although you shouldn't drive or make important decisions until the effects of sedation have completely worn off.
In most cases, your doctor will explain any findings before you leave the hospital and let you know when biopsy results, if taken, are expected. Whilst you are fully awake for this discussion, it is common not to remember what was discussed as the effects of the sedation wear off. You should receive a copy of your colonoscopy report when you leave the hospital.
Are there any risks with colonoscopies?
Whilst colonoscopies are generally considered very safe, every medical procedure has potential risks. Albeit rare, the most significant risks of colonoscopies are:
Bleeding, most commonly from the site where a polyp has been removed (either immediately or up to two weeks afterwards), and less commonly from injury to the spleen, which sits close to the colon
Perforation, which is putting a hole or tear in the colon
Failure to diagnose, meaning small abnormalities are missed (such as if the prep was inadequate and the colon not clean enough) or not finding the cause of symptoms
Complications of the sedation administered to perform the colonoscopy
Given these risks, it is important that careful consideration is given to the reason for performing a colonoscopy.
My doctor said he couldn’t finish the colonoscopy. What does this mean?
Most of the time, the aim of a colonoscopy is to visualise the entire large bowel, from the anus to the beginning of the colon, where it joins the small bowel. In some situations, this is not possible - this is medically termed an incomplete colonoscopy. The most common causes of this are:
Looping, where the colon is so long and floppy that coils form within it, making it impossible to get the colonoscope to the beginning of the bowel. The doctor may abandon the procedure to reduce the risk of perforating the bowel.
Tight angulations in the bowel
Stenosis, or narrowing of the bowel, such that it is too narrow to allow the colonoscope to pass. Common causes include diverticular disease, cancer, or inflammation. In some situations, a narrower colonoscope may be used.
Inadequate bowel preparation, where stool remaining in the colon makes it unsafe or futile to continue advancing the scope
Patient discomfort, where pain persists despite sedation
Adhesions from previous abdominal or pelvic surgery, which can fix the colon in a position that makes it difficult to pass the scope through
In these situations, the doctor may plan to have another attempt at colonoscopy, or order a special CT scan of the colon (a ‘CT colonography’), in which air is blown into the bowel to allow visualisation of its lining.
What is a ‘flexible sigmoidoscopy’
You may have heard your doctor say that instead of a colonoscopy, they are going to perform a 'flexi sig'. This is essentially a 'mini-colonoscopy', where instead of looking at the whole colon, only the last part of the bowel is visualised (usually just the rectum and sigmoid colon). The advantages of this procedure are that only an enema is required on the day, meaning you don't have to undergo full bowel prep. It also means that much lighter sedation is needed, or in some cases, no sedation at all. This procedure is only appropriate in certain circumstances, where it is considered unnecessary to visualise the entire colon.
How we can help
Every patient is different, and having a colonoscopy can bring up plenty of questions. Whether you're having the procedure for bowel cancer screening, ongoing surveillance or to investigate symptoms, understanding what to expect can make the experience much easier.
Dr Matt Marino provides personalised care, taking the time to explain your procedure, answer your questions and ensure you feel comfortable and informed throughout the process.
If you would like to arrange a consultation with Dr Marino, contact us here or call on 0493 318 188 to book an appointment.
