Patient Experience

  • Reference Number: HEY-953/2020
  • Departments: Endoscopy
  • Last Updated: 31 December 2020


This leaflet has been produced to give you general information about your procedure.  Most of your questions should have been answered by this leaflet.  It is not intended to replace the discussion between you and the healthcare team, but may act as a starting point for discussion.   If after reading it you have any concerns or require further explanation, please discuss this with a member of the healthcare team.


Where is the large bowel?

The diagram shows where the bowel can be found in the human body.

What is a Colonoscopy?

This is an examination of the large bowel using a long, flexible tube called a colonoscope. The tube allows the colon to be viewed directly and for pictures of the lining and samples of the tissues to be taken.





Why has this examination been arranged for me?

You will have seen your doctor about concerns about your bowels. Your doctor has arranged for you to be seen by a bowel specialist (or his representative) in a clinic. Your doctor / specialist feel that this examination (colonoscopy) is the best way to investigate your bowel (colon) problems. In this way the whole of the large bowel is seen at one visit.

The benefits of this examination include the ability to take biopsies to analyse parts of the large bowel lining which may be abnormal. It also enables the removal of polyps without the need (in the vast majority of cases) for an operation. This can usually be done at only one visit.

What happens if I refuse the Colonoscopy?

This is your choice and there might be alternative examinations we can use instead. Your plan of care and treatment may change, as it is possible that some important information will be unavailable.

Please discuss this with your consultant and endoscopist.

What alternatives might be available?

Alternative examinations can be used to examine the large bowel. They are not suitable in all cases. These are:

Flexible sigmoidoscopy

This is an examination very similar to a colonoscopy, using the flexible tube to look at only the left side of the bowel. Its advantages include a much shorter procedure time – about 5 -10 minutes. It does not require people to be sedated, taking about 10 minutes to do. Again biopsies can be taken and polyps removed.

However, only one side of the large bowel is seen and we have no information about the other side. Therefore a normal finding only refers to this side. If polyps are found, then depending on the size and type of polyp, a colonoscopy is needed to make sure there are no polyps on the right side of the bowel.

Computerised Tomography Colonography (Virtual colonoscopy)

Virtual colonoscopy is a medical imaging procedure which uses X-rays and computers to produce two- and three-dimensional images of the colon from the lowest part, the rectum, all the way to the lower end of the small intestine and display them on a screen. CT colonography is less invasive than a colonoscopy because the test does not involve inserting a tube all the way around the colon. You will still need to take a laxative beforehand to cleanse your bowel. If anything is found you may have to return for an actual colonoscopy.

What are polyps and why is their removal so important?

Polyps are benign growths, which arise from the lining of the large bowel. They are very common and are often an unexpected finding during colonoscopy. Generally, they do not produce symptoms.

Their removal is important because some polyps, especially large ones, have the potential to change into bowel cancers. This can take up to ten years. We cannot tell, just by looking, whether polyps contain cancer cells or not. They need to be removed and looked at under a microscope.

Because of the risk of cancerous change in polyps, they are removed whenever they are found during the colonoscopy. If the polyps are large or if there is other disease present, the risk of bleeding and perforation are greater than a normal colonoscopy.

Therefore, if the removal of polyps is unacceptable to you or you prefer to have them removed at a later date following further discussion with your doctor, please inform the endoscopist before you sign your consent and the examination begins.

Please read all the information sent to you by the Endoscopy Department.

Does a colonoscopy have any risks I should know about?

Yes, there are.  Risk means complications may occur. It is important to note that serious complications during colonoscopy are rare.

Complication rates, that is, how often complications occur, vary across the United Kingdom. If you would like to know our rates for serious complications this can be discussed with you during your consultation.

Complications can be described as minor (mild) or major (serious):

Minor complications:

These complications are common and expected but do not last for long and do not cause serious harm.

They include feeling bloated after the examination with trapped wind, feeling faint and dizzy, cold sweats and occasionally feeling sick.

We do keep a close eye on you in recovery and in the majority of patients these subside either very quickly (15 – 20 minutes) or over a couple of days. Over this time bloatedness is common and comes and goes. As long as you are passing wind and going to toilet, this will settle down.

There is a small risk of bleeding from the bottom after colonoscopy. The entrance to your bottom, the anus, does have a very good blood supply and this is where piles are often found. The insertion of the camera can cause a little bleeding.  This should only be ‘spotting’ on the toilet paper or drops in the toilet bowl. It may take some days for this to subside.

Major complications:

These are complications, which can be serious, may lead to admission to hospital and sometimes an operation. On rare occasions these can be life threatening, especially in people with serious and/or unstable cardiovascular or lung problems.

It is important to stress major and serious complications are rare.

Complications, which can become serious and life threatening include:

Perforation of the bowel

A small tear may occur through the bowel wall. This can especially occur in thin, diseased bowel or when polyps are been removed. If it occurs you may begin to feel unwell, feel nauseous or vomit, your tummy may become hard, swollen and painful. You may feel hot and shivery. These symptoms can occur within minutes of the perforation or may slowly develop over days.

If you have any of these symptoms YOU MUST CONTACT your doctor or the hospital Endoscopy Department, or Ward 100 HRI (out of hours) as soon as possible.


This can occur especially after the removal of polyps. Although great care is taken to ensure there is no sign of bleeding after a polyp is removed, the contraction of the bowel after colonoscopy when getting rid of wind or when the bowels are next opened can cause the area where the polyp was to bleed.

You should expect a little bleeding, such as ‘spotting’ on the toilet paper or small drops in the toilet bowl. This usually subsides quickly. If bleeding begins to increase and large clots of blood are seen and /or you begin to feel unwell or faint, please contact your doctor immediately for advice and help.

Recent evidence puts the risk of perforation, sometimes accompanied by bleeding at 1 in 1000. This can be higher with the removal of large, difficult polyps, especially in the caecum. This is usually the thinnest part of the large bowel.


Some people, for reasons we still do not fully understand, are particularly sensitive to this drug. The breathing can be too shallow and too slow. In these cases we stop the examination, give more oxygen and if required we can give an antidote, which reverses the effect of the sedation. This is usually all that is needed and the person recovers with no ill or lasting effects.

In some cases, when people have another serious illness e.g., heart disease, stroke, unstable angina, severe asthma or chronic bronchitis, the sedation drug can cause difficulty in breathing. This is rare and is why we monitor breathing and heartbeat throughout; and why we give oxygen by nasal tubes.

If you have a known allergy or reaction to sedatives and anaesthetics, please let the endoscopist and your nurse know.

How do I prepare for the colonoscopy?

Please read the information leaflet.  Share the information it contains with your partner and family (if you wish) so that they can be of help and support.  There may be information they need to know, especially if they are taking care of you following this examination. Complete the health questionnaire provided as fully as possible.

To be able to see the lining of the large bowel you will need to have your large bowel empty and free of faeces. To do this we will send you sachets of a special powder to mix with water and drink.  Instructions for how to take these sachets should have come with your appointment time. If not, contact the Endoscopy Department – see contact numbers.

This ‘bowel preparation’ will cause you to have diarrhoea. Sometimes it works within 1 – 2 hours but both sachets need to be taken to be effective. You must drink plenty of fluid during this time. Avoid ‘fizzy’ drinks. You can lose a lot of fluid and you can easily become dehydrated making you feel unwell.

Please also avoid red jelly as this can be seen during the test.

If you have diabetes (especially taking insulin) or you have serious heart, lung or kidney problems, or are concerned that a health problem you have may be affected, then contact the Endoscopy Department at the hospital where you are having your examination (see contact numbers).

  • LATEX – Please inform the department if you have a confirmed latex allergy as this will affect your appointment time.
  • CJD (commonly known as mad cow disease) – Please inform the department if you have been notified that you are at risk of CJD/vCJD (Creutzfeldt-Jakob disease/variant Creutzfeldt-Jakob disease) for public health reasons.
  • PREGNANCY – It is important that you inform us if there is a possibility that you may be pregnant.  Any information you share with us will be kept strictly confidential.

Please contact the department if you have a pacemaker.

Due to the above or other individual reasons, we do admit some people to hospital for preparation and colonoscopy.

Due to the nature of the examination we ask you to undress. A private changing area is provided. Although a gown and privacy shorts are provided, you may also wish to bring a dressing gown with you.

With your appointment letter, a health questionnaire will be sent. Please complete this to the best of your ability. This forms an important part of assessing your ‘fitness’ for colonoscopy and the potential for complications to occur, so that action can be taken to eliminate or reduce these risks.

If your health has deteriorated whilst waiting for this examination, please inform your Endoscopy Department. Your co-operation with the above is extremely important, without this your colonoscopy could be delayed.

Will I be able to eat before my colonoscopy?

Some foods such as plain chicken (not in a sauce), rice, clear soups and Bovril-like drinks may be taken – please refer to your Bowel Preparation information leaflet.

You should have nothing to eat or drink for 2 – 4 hours before your examination time, to ensure that your stomach is empty.  You will receive sedation which will make you sleepy and relaxed. Sometimes people feel sick and even vomit during this test.  By keeping your stomach empty there is less likely of any fluid entering your lungs should you vomit.

Where will I have my colonoscopy?

The colonoscopy will be performed in the Endoscopy Department. Specially trained and experienced endoscopists and nurses work here and are very experienced in the performance of colonoscopy and the care it involves.

It will be done at Hull Royal Infirmary or Castle Hill Hospital depending on where your consultant is based.  Please make sure you go to the correct Endoscopy Department. Directions will be given with your appointment letter.

All the staff will endeavour to make your stay as easy and dignified as possible. Please do not be afraid or embarrassed to ask questions.

Who will perform my colonoscopy?

It may be your consultant, another experienced gastroenterologist, a surgeon or a nurse endoscopist who is experienced in performing this examination. In these cases, your consultant will be sent a copy of the result.

This Trust is a teaching hospital and has commitments to train both doctors and nurses in all aspects of endoscopy and care. Occasionally doctors and nurses who are undertaking endoscopy training may perform your procedure.  An experienced endoscopist will supervise them. Your permission will be requested in advance for this. You may decline and the supervising endoscopist will perform the endoscopy.

Should I take my tablets during my bowel preparation and before coming for my Colonoscopy?

If you are taking tablets prescribed by your doctor or other specialist, you should continue to take these as normal. There are some medications that may need to be stopped or reduced for a period of time before your colonoscopy.  You will be told if this applies to you.

If you are taking any of the following medications, please contact your Endoscopy Department for further advice and instructions.

  • CLOPIDOGREL (PLAVIX) – Please inform the department if you are taking these tablets as these may need to be stopped prior to your procedure.
  • RIVAROXABAN, DABIGATRAN, APIXIBAN –  These are blood thinning medications and usually have to be stopped for a period of time to reduce the risk of bleeding.
  • WARFARIN –  These are blood-thinning tablets and may have to be stopped for a period of time before colonoscopy due to the risk of bleeding.
  • INSULIN – For some people with diabetes, we may need to admit them to hospital for the day and night before the test. There is a risk that the bowel preparation for the examination and restricted diet could make the control of your blood sugar difficult and make your diabetes unstable.
  • IRON – If you take iron tablets then these are usually stopped for one week before the colonoscopy. Iron coats the inside of your large bowel making it very dark and difficult for the endoscopist to see anything. It is important to stop iron otherwise your colonoscopy will be cancelled and another appointment made.

If you have any concerns about whether to take your medications before your colonoscopy, contact your Endoscopy Department.

What happens to me in the Endoscopy unit?

Our friendly staff will greet you on arrival. They will let your nurse know you have arrived. If there are any delays you will be notified as soon as possible and be kept informed.

We will explain what to expect. You will need to remove your lower clothing and will be given a gown and privacy shorts to change into. A place to do this will be provided, ensuring your privacy. If you have a dressing gown please bring this with you.

We will ask questions about your general health and work through the health questionnaire that you kindly completed for us. Please feel free to ask questions.

We will check your blood pressure, pulse and oxygen levels, before your colonoscopy.

Colonoscopy involves the giving of intravenous sedation – a combination of drugs, which makes you sleepy, relaxed and provides pain-relief or Entonox which is gas an air and is self- controlled analgesia. To be able to do this a needle is inserted in a vein in your hand or arm. This is removed once the examination is finished and you have recovered from the sedation.

Your endoscopist and nurse will discuss the examination with you and will answer any questions you or a family member has. You will then be asked to read and sign the consent form.

If you need glasses to read, please keep them with you at all times do not leave them with a relative or tucked away in a bag or pocket.

You are then taken through into the examination room and asked to lie on your left side on the examination trolley. Your belongings will be put in a plastic bag and will be with you all the time.

Once in position, your nurse will attach a finger probe, which monitors your oxygen levels and pulse throughout and after the examination.

Sedative drugs may make your breathing slow and shallow; therefore we give you a little oxygen nasal tubes.

When the colonoscopy is finished, you will be kept on your side until the sedation has worn off. Eventually you will be able to sit up and have a cup of tea. This can take approximately 30 – 60 minutes.

How will I feel during and after the Colonoscopy?

This is just for information but may be very useful to your partner and family. The sedation we give may cause you to forget some or all of the examination. This varies from person to person. You may not remember much about it.

At first the endoscopist will examine your bottom with a finger. This allows lubricating jelly to be applied and to examine the first few centimetres of the large bowel, which is sometimes not seen by the camera.

When the camera is inserted into your bottom, air is gently passed into the bowel.

This opens up the bowel so the endoscopist can see where he/she is going.  At first you may feel that you want to go to the toilet. You may feel a little anxious and embarrassed that you will pass a motion.


The first part of the large bowel begins to stretch. This sends messages to your brain telling you to go to the toilet. It is the air that causes this feeling. You will not mess yourself. As the camera is gently inserted further into the large bowel, this feeling should ease, but may not totally go away.

The large bowel is not straight. It has twists and turns. Sometimes this makes it difficult to steer the camera around these bends. In these cases more air is used and sometimes a bit more pressure to the end of the camera to help push and pull the camera around the bend.

This can cause discomfort and varies from person to person. It may be an ache and you may feel bloated, especially under the ribs. Instinct tells you to hold your breath until it passes. Try to relax and control your breathing, with good gentle, slow deep breaths. Your nurse looking after you will help.

Sometimes it can be quite painful. You must let your nurse and the endoscopist know. We can stop and remove some air. Sometimes more sedative drugs are needed. The colonoscopy takes approximately 20 – 30 minutes.

What happens when the colonoscopy is finished?

You will be asked to stay on your side and the trolley is moved into the recovery room. Here a nurse will continue to monitor your recovery this will involve checking your blood pressure, pulse and oxygen levels at regular intervals.

Gradually, as you recover, you will be advised to get rid of any ‘wind’ that may be trapped in your large bowel. We do appreciate that this can be embarrassing but it is important you do ‘let it go’.

You will eventually be able to sit up and you will be offered a drink. As you continue to recover you will be able to get dressed fully again and rest in a chair where you will be offered a drink and a biscuit.

Please take care. Initially you may feel dizzy and a little disorientated when getting off the examination trolley.

If you live alone or you do not have anyone who can be with you, please contact your Endoscopy Department so that other arrangements can be made.

Do I really need someone with me after colonoscopy?

Yes, this is very important. The sedation given can have effects, which last some 24 hours after the colonoscopy. You can become forgetful and also sleepy again.

Your test may be cancelled if you do not arrange to have someone to collect you and stay with you for the next 24 hours.

We strongly recommend that for the next 24 hours you:

  • Do not drive
  • Do not return to work or operate machinery
  • Do not sign any important/or legal documents
  • Are not left alone, you may be at risk of injuring yourself
  • Are not left alone to care for children

Will I be told what was found and what happens next before I leave the Endoscopy unit?

Yes. Your nurse and the endoscopist will explain the results to you. Due to the sedation you may forget what has been said. This is why it is important to have someone with you. The information will be written down and further supporting patient information leaflets will be given if required.

Will I ever need a colonoscopy again?

This will depend on the reason for colonoscopy, what is found and whether it was possible to complete the colonoscopy examination.

Colonoscopy can be used for bowel screening. Some people have a family history or genetic predisposition to developing bowel polyps and/or cancers. Some may have had bowel cancers already removed. In this case regular checking of the bowel with colonoscopy is needed.

If polyps are found, they are removed. Depending on the type and size of the polyp, the bowel may need to be checked at regular intervals to ensure the polyp has been completely removed and no new ones have grown.

For some, despite following instructions and taking the bowel preparation to empty the bowel, the view with the camera is poor. The endoscopist cannot be certain that the entire large bowel has been seen. In these circumstances, a repeat colonoscopy is needed and an alternative bowel preparation may be prescribed.

Occasionally, people’s bowels have very severe twists and turns and it becomes too difficult for the endoscopist to get the camera all the way round. Sometimes, despite sedation, it is too painful for the patient and he/she asks the endoscopist to stop. In these cases a CT Colonography is needed to examine the rest of the large bowel.

If you do need a repeat colonoscopy, do not worry. It is not because something serious has been found but usually for the reasons described above.

Further information

Information about bowel disease and digestive diseases can be found on: Digestive Disorders Foundation –

Further information about your rights with regards to consent can be found in the following documents:

  • Department of Health (2001), Guide to Consent for Examination or Treatment
  • Department of Health (2001), Consent – What you have a right to expect
  • A Guide for Adults. (Available from the Endoscopy Department)
  • A Guide for Relatives and Carers. (Available from the Endoscopy Department)

These are free of charge.

Visit the Department of Health’s website at: and, for consent:

Useful contact numbers:

The Endoscopy Department, Castle Hill Hospital

Telephone                 (01482) 622069 (direct line)

Monday – Friday       8.00am – 5.00pm

The Endoscopy Department, Hull Royal Infirmary

Telephone                 (01482) 674790

Monday – Friday       8.00am – 5.00pm

Ward 100 Hull Royal Infirmary

Out of hours (01482) 674860

What do those words in the leaflet mean?

Biopsy – A sample of tissue is taken for analysis.

Caecum – The first part of the large bowel; this is joined to the small bowel.

Consent – This is the agreement between you and the endoscopist.  You are agreeing to have investigations or treatment and that you understand the purpose, benefits, alternatives and risks. You and the endoscopist during this process usually sign a consent form.

Colonoscopy – The examination of the inside of the large bowel using a long, flexible camera.

Endoscopy Department – The place where your procedure takes place

Endoscopist – This can either be your consultant, an experienced and trained doctor or an experienced and specially trained practitioner.

Perforation – A rare, but possible risk in which a hole or tear is made through the large bowel.

Polyp – A common, benign (not cancer) growth arising from the lining of the large bowel. They take some years to develop. Some polyps, depending on their size and type, have the potential to turn cancerous.

Polypectomy – The removal of a polyp usually performed at the same time as the colonoscopy.

This leaflet has been written with the help, support, advice and collaboration of:

  • Consultants in the Academic Surgical Department and the Department of Colorectal Surgery
  • Consultants of the Department of Gastroenterology
  • Staff of the Endoscopy Departments at Castle Hill Hospital and Hull Royal Infirmary

The patients and carers who have shared their experiences of colonoscopy with me and helped in auditing the information produced for readability, understanding and user-friendliness.

The patient pictures are reproduced with the permission of Health Press Limited from Neild P, Gazzard B. Patient Pictures – Gastroenterology, Oxford Health Press, 1997.



This leaflet contains important information about having a colonoscopy.  It provides information to enable you to make decisions about whether you are in agreement with the planned colonoscopyIt is extremely important that you have read this leaflet.

In particular it provides information about the purpose and intended benefits, side effects and risks of having a colonoscopy.  It also explains consent to undergo the procedure and where further information can be found and from whom.

 Sources of further information and contacts are given at the end of this leaflet.



I have read the Colonoscopy leaflet.  Yes No
I understand the information it contains.  Yes No
I understand the purpose of the colonoscopy, intended benefits and alternative tests  Yes No
I accept that that there are potential risks of colonoscopy which include bleeding and perforation (puncture, tear, hole) of the bowel and I have been given every opportunity to discuss this with my consultant and/or person performing the colonoscopy.  Yes No
I understand and accept that biopsies (samples of tissue) may be taken.  Yes No
I understand and accept that polyps will be removed if considered necessary by the endoscopist, due to the reasons explained in this leaflet.  Yes No
I feel I have had the opportunity to seek further information, ask questions and have received information and answers to my satisfaction.  Yes No

Patient Name ……………………………………………………………………………..

Signature ………………………………………………………………………………….

Date ………………………………………………………………………………………..



General Advice and Consent

Most of your questions should have been answered by this leaflet, but remember that this is only a starting point for discussion with the healthcare team.

Consent to treatment

Before any doctor, nurse or therapist examines or treats you, they must seek your consent or permission. In order to make a decision, you need to have information from health professionals about the treatment or investigation which is being offered to you. You should always ask them more questions if you do not understand or if you want more information.

The information you receive should be about your condition, the alternatives available to you, and whether it carries risks as well as the benefits. What is important is that your consent is genuine or valid. That means:

  • you must be able to give your consent
  • you must be given enough information to enable you to make a decision
  • you must be acting under your own free will and not under the strong influence of another person

Information about you

We collect and use your information to provide you with care and treatment. As part of your care, information about you will be shared between members of a healthcare team, some of whom you may not meet. Your information may also be used to help train staff, to check the quality of our care, to manage and plan the health service, and to help with research. Wherever possible we use anonymous data.

We may pass on relevant information to other health organisations that provide you with care. All information is treated as strictly confidential and is not given to anyone who does not need it. If you have any concerns please ask your doctor, or the person caring for you.

Under the General Data Protection Regulation and the Data Protection Act 2018 we are responsible for maintaining the confidentiality of any information we hold about you. For further information visit the following page: Confidential Information about You.

If you or your carer needs information about your health and wellbeing and about your care and treatment in a different format, such as large print, braille or audio, due to disability, impairment or sensory loss, please advise a member of staff and this can be arranged.

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