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This information page contains information about your procedure including the risks, benefits, alternatives to the test and what you might expect when you come to the hospital. If, after you have read it, you have any queries or concerns; please talk to us about any worries and ask any questions you may have.


The aim of this page is to enable you to make informed decision when you come for your procedure. It is important to us that you have understood the procedure, its risks and benefits before we ask you to sign your consent form. We will need to have your formal written consent before we can perform your procedure which will be done either by an experienced Registered Nurse or your Endoscopist.

Your appointment time in Endoscopy Unit is approximate, as some procedures may take longer than expected. We also deal with emergencies and these can take priority over patients with outpatient appointment. You should expect to be in the department approximately for most of the morning or afternoon.

Preparation for the procedure

The success of your procedure depends on how clean your colon (bowel) is. To achieve this, we will provide you with a diet regime which you will need to follow and you will have to take some laxatives the day before you come for your procedure. This usually results in diarrhoea which can be unpleasant.


Bowel preparation

You will need to take a special laxative which will be supplied to you (Picolax®, Citrafleet®, Moviprep® or Klean Prep®).

Please ignore the instructions on the sachets and follow those set out on the separate sheet of paper in this envelope, titled “Bowel Preparation Instructions”.

These instructions will tell you what you need to do for the week running up to your colonoscopy, and particularly how to prepare the day before the procedure. Depending what time your procedure is booked for, you will need to follow a special checklist of instructions.

If you do not understand the instructions or need any advice, please call the Endoscopy Unit on 01932 722747.

For Inpatients only

If you are already an in-patient at the hospital, the ward nurses looking after you will make sure you are prepared for the test beforehand, and afterwards you will recover in your hospital bed.


Eating and Drinking

Please follow the dietary instruction which you can find on the Bowel Preparation Instructions sheet.

You can have few sips of water up to four hours before your test.



Unless you have been advised otherwise, you should take your usual medicine normally with few sips of water. Please do remember to bring in the list of your medications.

  • Iron tablets: Stop taking your iron tablets at least one week prior to your appointment.
  • Diabetes: If you are diabetic, please inform the Endoscopy department so that we can schedule your appointment appropriately. Also do let us know about the medications you are on. You will also be given specific instructions on managing your diabetes while you are having your bowel preparation. For example, if you are a diabetic you should find an advice sheet along with this information. If you do not have the advice sheet, or you do not understand the instructions, please call the Endoscopy nurses on 01932 722747.
  • Blood thinning medications:: If you are on any blood thinning medication like Warfarin, Dabigatran, Apixaban, Rivaroxaban or anti platelet medication like Clopidogrel, please inform us as soon as possible as it may be necessary for you to stop taking your tablets for a limited time before the procedure.


What other preparations do I have to make?

You will need to arrange to have three days off work (i.e. the day before your test to take the laxative, the day of your colonoscopy and probably the day after, especially if the appointment is in the afternoon.

You MUST have a responsible adult to collect you after your colonoscopy and you MUST have someone responsible to stay with you overnight. Failure to do this may very well mean having to arrange another date for you.


What is Colonoscopy?

Colonoscopy is a test that allows the Endoscopist to directly inspect the inner lining of the colon (large intestine). This is done using an instrument called a colonoscope, which is carefully passed through the anus into the large intestine. The colonoscope is a long flexible tube, about the thickness of your index finger, with a bright light at its tip. The video camera on the colonoscope transmits images of the inside of the colon to a monitor allowing the Endoscopist to examine the lining of the colon for any disease or abnormalities.

During the examination, tissue samples or biopsies can be taken for analysis. The sample is removed painlessly by a disposable forceps passed down the endoscope. It is also possible to remove polyps during colonoscopy. Polyps are abnormal projections of tissue, rather like a wart, which the Endoscopist will want to remove and examine in more detail. Photographs may also be taken and will be kept in your medical record.

The examination is carried out by a trained doctor or nurse called an Endoscopist. Sometimes, however, the test may be carried out by an Endoscopist who is learning, under the close supervision of the experienced Endoscopist.


Why do I need a Colonoscopy?

Your doctor has referred you for this investigation for either of the following reasons:

  • To investigate bowel symptoms like alterations in bowel habit, blood in the stool, or unexplained anaemia.
  • If you are at an increased risk of colon cancer.
  • To identify and confirm abnormalities noted in the bowel at other tests like CT scan or barium enema.


Are there any alternatives?

Barium enema - This test can examine the large intestine using X-rays and barium sulphate. The barium sulphate coats the lining of your bowel, making it easier to see on X-ray. This test does not look at the lower part of your bowel, so you may still need to have a colonoscopy.

CT (computerised tomography) scan - This is a special type of X-ray machine that can give more details than normal X-rays. However, it cannot be used to take biopsies or remove polyps, so you may still need a colonoscopy.

Flexible Sigmoidoscopy - This is similar to a colonoscopy but only looks at the lower part of the bowel. If your doctor or nurse cannot diagnose your symptoms after this test, you may still need a colonoscopy.

Faecal occult blood test (FOB) - This checks for hidden blood in your stool, but you may still need a colonoscopy if this test is positive.

Although there are a few alternatives to this test, colonoscopy is the most accurate way to diagnose conditions of the bowel and the only means to obtain tissue samples which might assist with making an accurate diagnosis and thus help with treatment.


Will I feel any pain?

Colonoscopy is safe, but maybe unpleasant and at times uncomfortable. During the procedure air is introduced inside your colon to open up the bowel. This may cause abdominal cramping. This is normal and will pass quickly. You may also experience pain as the colonoscope is negotiated past difficult bends in the colon.


What options are available to help me during my Colonoscopy?

Sedation via a needle – A sedative injection can help you relax during the examination. It can sometimes make you drowsy which can help you tolerate the procedure. A sedative is different to general anaesthetic, its purpose is to help you relax and not ‘knock you out’.

Pain relief via a needle – The procedure is not painful but can be uncomfortable especially when we put air into your bowel. A pain relief injection will help you tolerate the procedure.

Because the sedation and the pain relief can cause drowsiness, you will not be permitted to drive home or take public transport. You must arrange for a family member or a friend to collect you from the Endoscopy Unit and you must have an adult to stay with you overnight.

There is a considerable variation in the way people react to this procedure and the sedation. The procedure is safe, but may be unpleasant and at times uncomfortable. We aim to use the sedation to help you relax within safe limits. We do NOT aim to send you to sleep but we will do our best to make the procedure as comfortable as possible.

Antispasmodic via a needle – A medicine called Buscopan can be given to relax your small bowel during the procedure; this will enable the doctor to perform the procedure safer. Please let us know when you come to the department if you suffer from a condition called glaucoma or if you suffer from any heart disease.

Entonox inhalation - Entonox is a gas that can help relieve pain. It is inhaled using a mouthpiece; this means you are in control of how little or how much you take. Entonox is quickly expelled from the body, which means you will not need to stay longer in the department. You will also be able to drive home and will not need somebody to stay with you overnight.


What are the possible risks of Colonoscopy?

Are there any risks / complications?

As colonoscopy is an invasive investigation, it does carry a small risk of complication.

These are related to either sedation or to the procedure itself.

  • Sedation: Very rarely sedation given during the test can affect your breathing, blood pressure or heart rate. Usually such side effects are short-lived. Trained nurses will closely monitor you and should there be any reason for concern, we will give you medicine(s) to reverse the effect of the sedative.
  • Perforation: The chance of this happening to you is 1 in 1,000 with a slight increase if you have a polyp removed. This complication rate is based on the national average, and the rate of occurrence of this is well within this figure at Ashford and St. Peter's Hospitals. If there is a suspicion of a tear, the Endoscopist will organise further tests like x-ray or CT scan. Should these tests confirm that a perforation has occurred, we will arrange for you to stay in hospital to have the right treatment.
  • Bleeding: There is also a very small risk of bleeding, either from the site of a biopsy or following polypectomy. In most cases this is trivial and subsides spontaneously; if not it can usually be treated by electrical cautery or other treatment like applying small clips.
  • Incomplete procedure: Please note that occasionally the test may need to be abandoned or may be incomplete. This can happen if you find the procedure too uncomfortable or if the bowel preparation did not empty your bowel completely. In this case, the test may need to be repeated or we may suggest an alternative procedure.


What will happen when I come in?

When you come to the Department, please present yourself at the Reception where they will confirm your details with you. You will be given a blue booklet where you will be asked to answer several health questions and write a list of your medication (please remember to bring a list of your medications with you when you come for your appointment). Please note that we have a limited amount of space in the Department and there may not be an available space for a friend or relative to accompany you during your appointment.

A member of staff will bring you in the Admissions area to go through your health questionnaire with you. He/she will be taking your blood pressure, pulse and temperature and record it in your booklet. An intravenous cannula will be placed in your arm/hand if you have chosen to have sedation; this will be used as an access so the Endoscopist can give you the sedation before the start of the procedure. Your admission nurse will make sure that the procedure is thoroughly explained and that you understand the procedure before you sign your consent form. This will be an opportunity for you to ask any questions you may have. The member of staff will also ask you about your arrangements for getting home after your colonoscopy. If you decided to have sedation, a responsible adult must be available to take you home and stay with you overnight, as the sedation can impair your reflexes and judgment.

Please note that your procedure will be cancelled if you do not have an escort arranged to collect you from the Department.

We will be asking you to sign your consent before you can be taken into the procedure room where your endoscopy will be done.


What happens during a Colonoscopy?

Your procedure will be carried out in one of the procedure rooms where experienced members of the team will be with you at all times. A member of staff will put a blood pressure cuff on your arm and a probe will be placed on your finger to check your oxygen level throughout the procedure, a plastic cannula will also be placed in your nostrils if you requested to have sedation. You will be asked to lie on your left-hand side, if you have requested to have sedation, it will be given at this point.

The Endoscopist will then introduce the colonoscope through the anus into the rectum and advance it around the colon whilst inspecting the lining for any abnormalities. The entire examination takes between 15 minutes to an hour. If during the test any abnormality is detected requiring specific treatment given through the endoscope, the procedure might take longer.

Photographs may be taken during your procedure; these will be filed and kept in your medical notes.


What happens after a Colonoscopy?

Following the test you will be transferred to the recovery area. You must expect to stay on the Endoscopy Unit for at least 1 hour after your colonoscopy and up to two hours if you have a polyp removed. Your blood pressure, heart rate and oxygen levels will be monitored to ensure a safe recovery.

If you are diabetic, we may need to check your blood sugar again. Once you are fully awake from the sedative, you will be offered some refreshments like tea/coffee and biscuits. The plastic cannula used to give you the sedation will also be removed. The sedative can make you forgetful and can make you feel intermittently tired and drowsy for at least 24 hours, this is why we strongly recommend that you arrange someone to stay with you overnight. For 24 hours following your sedation, you must not drive, drink alcohol, operate any heavy machinery or sign any legal document. If the person collecting you has left the Department, a member of staff will telephone them when you are ready to go home. Once your escort has arrived, you will be taken to a private room where a member of staff will go through all your discharge information with you. After this and you feel ready, you could be discharged from the Department. A copy of your endoscopy report will be given to you.

If you received Entonox® only, we will keep you in Recovery for at least 30 minutes (and up to 2 hours if a polyp had been removed) and will monitor your vital signs. After half an hour and your vital signs are within normal limits and you are not in any discomfort, we will ask you to change back into your clothes. After this, we will ask take to the secondary discharge where we can offer you some refreshments like tea/coffee and biscuits.

When you are ready to go home, a member of staff will bring you to a private room where we can explain to you the results of the endoscopy. A copy of your endoscopy report will be given to you.


When will I know the results?

An experienced member of the team will be able to tell you the endoscopy results when you are ready to go home. However, if a biopsy sample was removed, this might take up to six to eight weeks to process (depending on the urgency). We will write to you and GP with the result or arrange an outpatient appointment, whichever is appropriate.


When can I return to work?

If you do not have sedation, you can return to work straight away. If you have sedation, you should be well enough to return to work after 24 hours.


What would it mean if I did not have the Colonoscopy?

If you did not have the Colonoscopy, your condition would not be accurately diagnosed and, without the right treatment, could get worse.


Can I seek a second opinion?

Yes, if you are not happy with the results, treatment or advice, you have the right to seek a second opinion and your Doctor can advise you on that tissue if required.