Having a Colonoscopy

A Colonoscopy is a procedure which examines the lining of the large bowel (colon). The instrument used is called a colonoscope (scope). The scope is a flexible instrument which enables light to be directed onto the lining of the bowel wall and relays pictures back to a television screen. It allows inflation of air or carbon dioxide to help the passage of the scope and also aids clear views. Due to the inflation of air/carbon dioxide you may experience some bloating or discomfort throughout your Colonoscopy and for a period afterwards.

Colonoscopy may identify the cause of your symptoms and help decide further management towards treatment or other investigations. Polyps (small growths) can be detected and can often be removed through the colonoscope usually at the same time of your procedure (please see more information on polyps later in this booklet). If you have had a CT Colonography, x-ray or ultrasound scan which has shown a suspected abnormality in the large bowel, Colonoscopy allows a closer examination of this area. Colonoscopy is also performed as a follow up from previous polyps or other disease of the large bowel.

A CT (computed tomography) colonography is a test that uses CT scans to check the larger bowel (colon). It is also called virtual colonography. You are required to take bowel preparation beforehand as with Colonoscopy. If anything abnormal is found sometimes a Colonoscopy is required to allow a closer look at the bowel lining and to allow samples (biopsies) to be taken for diagnosis.

Colonoscopy is classified as an invasive procedure therefore there is a risk of complications. These complications are rare, but it is important that you know about all the risks before you decide to go ahead with the procedure.

Despite using sedation and painkillers some patients may experience abdominal discomfort or pain and request the procedure to be stopped before completion.

There is also a small chance that the Endoscopist may not be able to pass the colonoscope along the entire length of the bowel and have to abandon the procedure. An alternative investigation will then be needed.

Perforation or tear of the bowel lining (about 1 in 1,000 procedures) In this case you would be admitted into hospital and may require an operation. This risk increases when a Polypectomy is performed.

Bleeding may occur after biopsy or polypectomy (about 1 in 150). This more commonly happens after the procedure and will usually stop on its own, however you may require admission into hospital and occasionally need a repeat endoscopy or an operation.

Sedation can occasionally cause problems with breathing, heart rate and blood pressure. If any of these problems do occur they are normally short lived. Careful monitoring by a trained Endoscopy nurse will ensure that potential problems can be identified and treated rapidly.

When you arrive at the department please book in at reception. Your details will be checked and you will need to give contact details of the relative/friend who will be collecting and staying with you if you are having sedation for your procedure.

It is our aim for you to be seen as soon as possible for your procedure. If the department is very busy, your procedure may be delayed therefore, you must allow enough time to be on the unit for the full morning or afternoon of your procedure. The department looks after emergency patients too and these patients will take priority if needed. If you take warfarin please let the receptionist know at this point so we can take a blood sample for your warfarin levels.

You will then be seen by a qualified nurse or health care assistant for your pre assessment. They will ask you some questions and about your general health. They will also record your blood pressure, pulse, oxygen saturation and weight. Please bring a list of current medication you are taking (a repeat prescription or actual medications). If you have any outstanding concerns or questions please take this opportunity to discuss them with the nurse at this point.

You will be seen by the Endoscopist, to ensure you understand the procedure and the risks associated with it and if you have not already done so and are happy to proceed you will be asked to sign your consent form.

A nurse will escort you to the procedure room where your details will be checked once again and you will be introduced to the other members of staff in the room. You will have the opportunity to ask any final questions. You will be asked to remove your lower garments and put on a hospital gown, behind a curtain, and then asked to lie on the trolley on your left hand side with your knees bent and will be covered with a sheet. During your procedure you may be asked to move into different positions to aid the passage of the colonoscope.

A probe will be attached onto your finger which will record your pulse and oxygen saturation throughout your procedure. Your blood pressure may also be recorded.

A small sponge which sits just inside the nostril may be inserted if oxygen administration is required during your procedure.

A cannula may be inserted into a vein in the back of your hand or your arm to allow the administration of sedation or other medications if needed.

The Endoscopist may examine your back passage with a gloved finger before inserting the scope. The Colonoscopy involves manoeuvring the scope around the entire length of you large bowel. There are some bends which naturally occur and negotiating these may be uncomfortable but this should not last long. You may feel bloated due to the air/carbon dioxide that is used.

Wearing loose fitting clothing that is not tight or fitted around your waist would be more comfortable for after the procedure.

The procedure takes about 30-40 minutes (but can take up to an hour).

If you require Entonox (gas and air) for your procedure you will be given instructions on how to inhale it by the trained nurse looking after you.

Entonox is a powerful painkiller with very rapid onset of action and is quickly eliminated from the body. It is a mixture of 50% nitrous oxide and 50% oxygen that provides rapid, safe and effective short term pain relief without loss of consciousness it also has properties that can reduce any anxieties.

Please inform the nurse if you have any of the following as Entonox in the cases listed below should not be used.

• Undergone recent eye surgery involving gas bubble insertion
• Head injury
• Pneumothorax
• Abdominal distension
• Suspected intestinal obstruction
• Bullous emphysema
• Middle ear procedures i.e. myringoplasty
• Following a recent dive
• Severe injuries to the face and jaw

Please note: Although the manufacturers recommendations are that you can drive 30 minutes after using Entonox, we do recommend that you do have someone to drive you home.

Sedation will make you lightly drowsy and relaxed but not unconscious. It is not a general anaesthetic. You will be in a state of consciousness this means that, although drowsy you will hear what is said to you and therefore will be able to follow simple instructions during your procedure. There is no pain killing effect with sedation.

Please note, if you are going home following sedation it is important that someone comes to collect you, and a responsible adult stays with you for approximately 24 hours. Once home it is important you rest quietly for the remainder of the day. Sedation lasts longer than you think!

For 24 hours after sedation you must not drive, drink alcohol, operate machinery, and travel by public transport or sign any legally binding documents.

IF YOU DO NOT HAVE AN ESCORT, WE CANNOT GIVE YOU SEDATION.

A polyp may be detected during the Colonoscopy. This is an overgrowth of the cells which protrudes from the bowel wall. The type of cell that forms the polyp varies and is important in determing its potential for growing and later causing problems.

Most people with polyps do not have any symptoms at all. However, sometimes polyps may bleed or produce excess mucus (slime) that may be noticeable on motions. If polyps are very large they may cause diarrhoea or constipation. Very rarely a polyp may grow so big it causes a partial or total blockage of the bowel and this may give rise to abdominal pains and/or bloating.

Some polyps have a stalk (pedunculated) and look like a mushroom, whereas others are flat (sessile) without a stalk.

Polyps can often be removed (polypectomy) by the Endoscopist performing the Colonoscopy.

A polyp may be removed in one or two ways both using an electrical current known as diathermy.

For pedunculated polyps a wire loop (snare) is placed around the stalk of the polyp and a high frequency electrical current is passed through the wire loop which cuts through the polyp and cauterises any blood vessels.

Sessile polyps are usually removed by a procedure called EMR (Endoscopic Mucosal Resection). This involves injecting fluid into the lining of the bowel that surrounds the polyp to raise the area from deeper layers, allowing the snare to capture and remove the polyp.

Very small polyps may be pinched off the bowel wall with small forceps.

Please note: for safety reasons very large polyps may not be removed on the day of your Colonoscopy, you may be scheduled a longer time slot appointment for your polypectomy.

After removal, polyps are sent to the laboratory to be looked at under a microscope. You will receive these results either at your next clinic appointment or the Endoscopist will write to you with the results. Results are usually available within 2-3 weeks.

After Polypectomy, sometimes further Colonoscopies are needed (1, 3 or 5 years later) to check if you have developed any further polyps. You will be advised of this by the Endoscopist.

After removal of large polyps there is a risk of bleeding and/or a perforation forming in the bowel wall while the area heals. The healing process can take up to 2 weeks.

If you have had a polyp removed there is no need to alter your general activity afterwards. However, it is important to inform the Endoscopy Unit between 8am and 6pm Monday to Friday (excluding weekends and bank holidays) or the Accident and Emergency Department out of these hours if you pass any fresh blood or clots (more than a tablespoon) or if you have severe pain and swelling in your abdomen which persists and does not improve.

You will be taken into the recovery area where you will be allowed to rest for as long as is needed. Your pulse, blood pressure and oxygen saturation levels will be monitored and when the recovery nurse feels you are ready you will be allowed a warm drink and a biscuit. You will then have your cannula removed and you will be able to get dressed. The nursing staff will contact the person collecting you when you are ready for discharge.

The nurse or Endoscopist will discuss the findings with you and any medications or further investigations that might be required. You will also be given written information on what to expect after your procedure and may also be given a copy of the Endoscopy report to take home with you.

It is important that your large bowel is clear so that we can get clear views of the lining of your bowel. You will have been given a laxative medication (often referred to as “bowel preparation” or “bowel cleansing solution”) this will cause you to have watery stools.

The instructions are different for morning and afternoon appointments so please make sure you check your appointment time. (Afternoon appointments start at 12.30pm).

If you are taking Iron tablets you should stop taking them 7 days before your appointment.

If you are taking stool bulking agents (e.g. Fybogel, Regulan, Proctofibe), Loperamide (Imodium), Lomotil or Codeine Phosphate please stop taking these 3 days before your appointment.

If you take strong pain killers and would find it difficult to stop taking them before the test please speak to your GP as you may need a regular laxative for a few days before you start taking the bowel preparation.

If you are Diabetic you should have received a separate information booklet relating to your medication. If you have not received this booklet please contact the Endoscopy unit to receive a copy.

If you take anticoagulant medication such as Warfarin You should have been advised by the doctor requesting your procedure if you need to stop taking it before your appointment. If you haven’t been given any instructions regarding your medication please contact the Endoscopy unit on 01709 427029.

You will have your INR checked on arrival at your appointment.

If you are taking antiplatelet medication such as:

• Clopidogrel (Plavix)
• Aspirin
• Dipyridamole

You should have been informed if you need to stop it before your procedure. If you have any quires please contact Endoscopy on 01709 427029.

Other medications which you should temporarily discontinue when you start taking your bowel preparation:

• Antihypertensive (to lower your blood pressure) such as ACE inhibitors like ramipril
• Diuretics (water tablets)
• Non-steroidal anti-inflammatory drugs such as Ibuprofen and Diclofenac

If you have not received specific advice regarding any other regular medications, then you should continue to take them as normal.

However, you may need to alter the times when you take them. It is preferable to avoid taking them less than 1 hour either side of any dose of your bowel preparation as the absorption of some medicines may be affected.

If you are taking the contraceptive pill you should take alternative precautions until your next period following any bowel preparation.

If you are still unsure about your medication, please contact the Endoscopy Nursing Staff who will advise you. 

Please read your bowel preparation instruction leaflet. It is important that you follow these instructions especially with regard to the amount of fluid you should drink, as bowel preparations can cause you to be come dehydrated.

Symptoms of dehydration include dizziness or light headedness (particularly on standing up), thirst, headache or reduced urine production (passing less water).

For booking/changing appointments:
Telephone: 01709 427277 / 01709 427278 / 01709 427279 / 01709 427377

For any medication, diet or any other queries relating to your procedure, contact Endoscopy recovery
Telephone: 01709 427029

Endoscopy Service
Telephone: 01709 424439