Colonoscopy

This leaflet has been written by staff working in the Endoscopy Unit at Chelsea and Westminster Hospital.

We hope you find it useful. If, after you have read it, you have any questions or concerns, please ring us on our direct line 020 3315 3056/5223.

When you come into the Unit (2nd Floor, Lift Bank B), please talk to us about any worries and ask any questions you have. 

If you would like to change your appointment time or date, please contact the Endoscopy Unit booking team on chelwest.cwdiagnosticcentre.admin@nhs.net or 020 3315 4141/5984.

Your appointment time in endoscopy is approximate because some procedures may take longer than expected and emergency procedures need to take priority. Please expect to be in the department for several hours—having pre-procedure checks, the procedure and for recovery after the procedure.

What is a colonoscopy?

A colonoscopy is a diagnostic test in which a long flexible telescope called an endoscope is passed through the back passage (anus) allowing the doctor to look directly at the lining of the large bowel (colon).

Sometimes a biopsy—a sample of tissue—is taken for analysis (testing) in the laboratory. The tissue is removed through the endoscope using tiny forceps. It is also possible to remove polyps during the colonoscopy. Polyps are abnormal growths of tissue, similar to warts, that normally should be removed and examined more closely. This is not painful.

There is a considerable variation in the way people react to this procedure and the sedation. General anaesthesia is not required. The procedure is safe but may be unpleasant and, at times, uncomfortable.

If you chose to have sedation, we aim to use enough sedative to relax you. We do not send you to sleep but we will do our best to make you as comfortable as possible. Some people will not remember all of the procedure after having the sedative, this is normal and nothing to worry about.

What should I do before I come in?

7 days before procedure

Please stop taking iron tablets (including vitamin tablets that contain iron) and bulking agents (Fybogel or Regulan) one week before the test.

4 days before procedure

Stop taking any constipating agents (loperamide, codeine phosphate etc) but continue any other medications and laxatives until your appointment.

For the 4 days before procedure

You will need to follow a restrictive diet to achieve optimal views of the bowel. Eat only low fibre foods and avoid all high fibre foods. Please see our separate dietary sheet.

Bowel preparation 

The success of the colonoscopy depends on how clean your colon is. Cleansing your colon before a colonoscopy is called bowel preparation.  It involves drinking sachets of bowel preparation (laxative) to empty your bowels before your test. It is very important you read and follow the bowel preparation instructions and the low fibre diet before your procedure.  Please see enclosed leaflets.

Collect your bowel prep medicine

Please collect your bowel prep medication on the time and date booked for you. If you would like to change the collection appointment, please call the numbers on your letter. If you do not collect your preparation, your procedure will be cancelled and you may be discharged back to your GP.

Unless advised otherwise, if you are taking any of the following medicines, please inform the pre-assessment nurse or a member of the Endoscopy team for further instructions:

Note: Please take your simeticone (Infacol) 30ml (1,200mg) 6-8 hours or as instructed prior to procedure using your 30ml plastic cup.

On the day of the colonoscopy

Continue drinking clear fluids until two hours before the procedure.

What are the benefits and risks?

The benefit is that this procedure will help us to investigate your symptoms and may help us to treat you. There is a small risk of complications during the procedure. There is an extremely small risk of bleeding (hemorrhage) and a tear in the lining of the bowel (perforation) occurs in 1 in 1500. These complications are rare, but may require urgent treatment, blood transfusion or an operation.

It may be necessary to remove polyps. If this happens, the risks are slightly higher, bleeding in 1 in 50 or a tear in 1 in 250.

Occasionally the procedure cannot be completed and we would normally recommend a special CT to look at the bowel (CT pneumocolon).

What options are available for the procedure?

Sedation via a needle If you chose this we will give you a sedative via a needle in your arm. This is not a general anaesthetic but will make you relaxed and may make you feel sleepy. If you have sedation you will need to rest on a trolley here for at least an hour afterwards until the effects of the sedation have worn off.

Please note with sedation, even if you feel wide awake your reactions may still be affected. You may find it difficult to concentrate and you may forget things that you have been told after the procedure. The nurses will give you written discharge information. This includes the advice that for 24 hours after sedation you should not drive, ride a bicycle, operate machinery, take sedatives or drink alcohol, or sign legal documents. 

If you have sedation, your escort must collect you from the unit, take you home and be with you for the next 24 hours. We cannot escort you home. If you do not have an escort, you may choose to have Entonox Only.

Entonox (gas and air) If you chose this you will be given Entonox to breathe in as needed during the procedure. The gas takes immediate effect and helps relieve discomfort but does not make you feel sleepy. If you chose this option you do not need an escort to take you home after. 

What will happen when I come in?

On admission to the unit a nurse will ask you several questions about your health, current medication (please bring an up to date list with you), take your blood pressure and pulse, and ask you to get changed into a gown and dignity short which are specially designed to maintain patient modesty before, during and after a colonoscopy procedure.

Please leave any valuables at home, as we cannot be responsible for any valuables lost whilst you are in the unit.

You do not need to bring anyone with you to your appointment, unless they are acting on your behalf (e.g. interpreting for you).  Your escort/relative will only be needed when you are discharged if you have sedation.

Prior to the test you will be seen by the endoscopist. This is an opportunity to discuss the test before you sign a consent form. Please ask any questions you may have. It is important that you understand what is going to happen.

What will happen during the procedure?

In the procedure room you will lie on a trolley (narrow bed) on your left side. A nurse and the endoscopist will stay with you throughout the test.

During the test you may be given oxygen through little prongs that fit just inside your nostrils. Your blood pressure, pulse and oxygen levels will also be monitored.

The doctor will perform the colonoscopy by passing the endoscope into your bottom. During the test air is passed down the endoscope into your bowel to expand it, so the doctor has a clear view of the lining of your bowel. This may give you some wind like pains and may also make you need to pass wind.

Although this can be embarrassing, remember the staff do understand what is causing it and the air is sucked out at the end of the test. You may also get the sensation of wanting to go to the toilet, but as the bowel is empty, there is no danger of this happening. This sensation is normally due to the air we have pumped in.

The test lasts from 15–60 minutes. If you need treatment given through the endoscope, this may take longer. If this applies to you it will be discussed when your appointment is made.

FAQs

Will I get the results of my test on the same day?

A: Before you go home you will be given the results of the test. It will also say whether you need an appointment with a consultant or with your GP. Your GP will receive a copy of the report of the examination from the hospital. If biopsies were taken these results take longer and will be sent to your consultant and GP.

What happens to my medication?

We will talk to you before you go home about any changes/additions to your medications.

What can I expect when I go home?

You may experience bloating and stomach discomfort for a few hours after the test. This is because of the air that is used to expand and inflate your bowel during the test. These symptoms are often relieved by passing the wind.

If you have had a polyp removed or a biopsy, you may experience a little bleeding from your back passage.

Some patients have told us that they experience discharge from their back passage or an urgent need to open their bowels after the procedure. You may therefore like to bring a change of underwear and some incontinence pads with you to your appointment.

If the pain continues or are passing large amount of blood, or are passing large amount of blood, or you have concerns or questions, please contact the Endoscopy Unit from 8am–6pm on 020 3315 3056/5223

Outside of these times please call St. Mary Abbot ward on 020 3315 8602 / 8603 or go to your nearest Accident and Emergency and remember to take your Endoscopy report with you.