A colonoscopy is a valuable diagnostic procedure to investigate and detect the cause of bowel symptoms.
During a colonoscopy, the doctor inserts a thin, flexible tube with a camera on the end into your back passage (rectum). The equipment relays images to a screen so the doctor can check your lower bowel. Colonoscopies generally take between 30 to 40 minutes.
Colonoscopies are available both on the NHS and privately. If you choose to go private, you’ll need to have a consultation with your chosen doctor beforehand so they can discuss your symptoms, current health and medical history to determine if a colonoscopy is right for you.
If your NHS doctor refers you for a colonoscopy, you can ask to self-refer to a private consultant instead. With the support of PHIN, you can access a list of local, private colonoscopy consultants with ease so you can access the care you need.
Although colonoscopies are a relatively simple procedure, you will need to prepare. Preparing for your colonoscopy involves changing your diet, fasting and taking laxative medications. Discover more about how you can prepare for your colonoscopy below.
Stopping supplements or medications
Generally, you don’t have to stop taking regular medications for a colonoscopy.
However, you may need to stop taking iron tablets (prescription or supplemented) or any other medicines that can cause constipation a week before the procedure. This precaution is so the laxatives (medicines that help you poo) you are given in preparation for your colonoscopy can efficiently clear your bowels of stools. Only take laxatives if they’ve been provided – do not take your own.
If you take blood thinners (anticoagulants) or have diabetes, you must tell your consultant immediately, as they may give you a different diet and fasting instructions to follow.
What to eat before your colonoscopy
Once you have booked your colonoscopy, you’ll receive a timeline from your consultant showing when you’ll need to change your diet. Most people only need to change it up to two days before their appointment.
You must change your diet temporarily so the consultant can see your bowel clearly on the images. It also helps the laxatives to empty your bowels.
Your diet two days before the colonoscopy must consist of plain foods only. You must also decrease your fibre intake.
Learn more about following a low fibre diet before your colonoscopy .
You can eat foods like:
- Plain chicken (with no sauce)
- White rice
- White pasta
- White bread
- Clear soup (broths)
You will also only be allowed to drink clear fluids such as:
- Water
- Black tea
- Black coffee
- Squash (without red or purple food colouring, as these can discolour your colon’s lining)
Your private consultant will list what you can and can’t eat, so follow the guidelines carefully. If you don’t, your procedure may need to be rescheduled.
Can I eat before my colonoscopy?
You cannot eat anything on the day before your colonoscopy and you must only drink clear liquids. It’s vital to stay hydrated, as you will lose a lot of water later when taking the laxative supplements.
You can’t eat on the day of your colonoscopy either – not until the procedure is complete.
Bowel preparation: using laxative medications
The day before your colonoscopy, you must drink sachets of laxatives to empty your bowels.
Usually, you’ll need to drink multiple sachets and space them out throughout the day. The laxatives will cause diarrhoea, so staying at home near the toilet is essential once you start drinking them.
The laxative sachets usually are one of the following medications:
- Polyethylene glycol
- Magnesium citrate
- Magnesium hydroxide
- Bisacodyl
- Sodium picosulfate
Colonoscopy consultants favour different types of laxatives, but they will all come as a sachet you must drink when instructed.
Some people find the laxatives’ taste unpleasant and find it challenging to drink the recommended dose.
However, you could try these tips, which may help it go down more easily:
- Keep it chilled in the fridge
- Drink it with a straw kept towards the back of your mouth
- Follow it up with a sip of a clear liquid you like the taste of
Are there any alternatives to the laxatives?
If you think you may struggle to complete your bowel prep with the laxatives provided, let your consultant know quickly. They might recommend alternatives and will reschedule your appointment if necessary.
One possible alternative is an enema, where the consultant inserts a liquid directly into your back passage to encourage you to empty your bowels. However, enemas are limited cleansers as they do not reach all parts of the colon required for a colonoscopy.
You can sometimes have enemas together with laxatives. However, always speak with your consultant before stopping your laxative sachets or trying alternatives, as they may be unable to complete the procedure if your preparation isn’t adequate.
Find your local colonoscopy consultant with PHIN
PHIN can help if you need a local, private specialist to perform a colonoscopy. We’re committed to providing you with the support you need to access the private healthcare you deserve.
Our easy-to-use search tool helps you find consultants who specialise in colonoscopies and are close to home. We’ll give you the necessary information, including their fees, patient reviews and location in a comprehensive profile.
With PHIN’s support, search for local consultants and hospitals near you for your private colonoscopy today.
Other diagnostic ‘scopes’
You can read more about other diagnostic procedures, including endoscopy in the Help and Advice section on our website.
References
- Colonoscopy: Getting ready. NHS. https://www.nhs.uk/conditions/colonoscopy/getting-ready/, last reviewed 14 November 2022.
- Colonoscopy. NHS. https://www.nhs.uk/conditions/colonoscopy/, last reviewed 14 November 2022.
- Colonoscopy: Why it’s done. NHS. https://www.nhs.uk/conditions/colonoscopy/why-its-done/, last reviewed 14 November 2022
- Colonoscopy. Cancer Research UK. https://www.cancerresearchuk.org/about-cancer/tests-and-scans/colonoscopy, last reviewed 4 August 2022
- Stauffer CM, Pfeifer C. Colonoscopy. StatPearls. https://www.ncbi.nlm.nih.gov/books/NBK559274/, last updated 24 July 2023.