Blood Sugar Monitoring

If you usually test your blood sugar levels, check them, as usual, on the morning of the procedure and bring your monitoring equipment with you to the appointment. 

If you do not usually test your blood, do not worry, your blood levels will be checked when you arrive for the procedure.

People taking diabetes tablets

Day before colonoscopy – clear fluids only

Aim to have carbohydrate at your usual meal times from the list of permitted clear fluids. You can have sugary fluids, fruit juice or fruit jelly to replace your usual carbohydrates

• If taking Metformin do not take until you are eating again after the colonoscopy 
• If taking Rosiglitazone (Amaryl) or Pioglitazone (Starlix) do not take until after the colonoscopy. 
• If taking Gliclazide, Glibenclamide, Tolbutamide, Repaglanide or Glimepiride take half your morning dose and do not take again until after the test.

The day of the colonoscopy

• Do not take your morning dose of tablets; bring your tablets with you to have after the procedure 
•  Report to the nursing staff if you have needed glucose before arriving and inform them immediately if you feel ‘hypo’ at any time during your visit 
• Your dosage of tablets can be given as soon as you are able to eat and drink safely; the nursing staff will inform you when this is safe.

People on insulin

Day before the colonoscopy

• Aim to have carbohydrate at your usual meal times using fluids from the list of permitted clear fluids. 
• You will need to reduce your usual insulin doses to avoid the risk of hypoglycaemia (low blood sugar). You should reduce each of your insulin doses by at least a third except if taking Lantus or Levemir. This should be continued at the normal dose.
•  If you have concerns about adjusting your insulin dosage please contact the Diabetes Nursing Team well in advance of the appointment to discuss appropriate measures.

Day of the colonoscopy

• Do not take your morning dose of insulin; bring your insulin with you to have after the procedure. n If you take Lantus or Levemir continue your normal dose 
• Report to the nursing staff if you have needed glucose before arriving and inform them immediately if you feel ‘hypo’ at any time during your visit. 
• Your morning dose of insulin can be given as soon as you are able to eat and drink safely; the nursing staff will inform you when this is safe.

General points to remember

•  It is our aim for you to be seen and investigated as soon as possible after your arrival. However, the department is very busy and your investigation may be delayed. If emergencies occur, these patients will obviously be given priority over the less urgent cases. 
•  The hospital cannot accept any responsibility for the loss or damage to personal property during your time on these premises. 
•  If you are unable to keep your appointment please notify the endoscopy department as soon as possible. 
• Because you are having sedation, please arrange for someone to collect you. 
• If you have any problems with persistent abdominal pain or bleeding please contact the Endoscopy Helpline for advice. Contact details will be on your discharge letter.

Specific advice for people with diabetes

Treatment by diet alone

If you control your diabetes with diet alone, you simply need to follow the instructions given to you to prepare for your colonoscopy.

Treatment by tablets and/or insulin 

You should inform the endoscopy department about your diabetes and request an early morning appointment.

Preparation on first day 

As advised earlier in this Booklet there are two days of preparation before the examination. When following the low fibre diet on the first day try to make sure you eat your usual amounts of carbohydrate from the allowed list eg white bread, white rice, pasta etc. Continue to take your usual tablets and/or insulin and check your blood sugar levels as usual. 

Adjusting your diabetes medication to prevent hypoglycaemia 

You will need to reduce your treatment the day before and the morning of the procedure to prevent the risk of hypoglycaemia (low blood sugar level). As a result your blood sugar control may be a little higher than usual. This is only temporary to maintain your blood sugars through the procedure and you should be back to your usual level of control within 24 to 48 hours. 

If you have concerns about adjusting your dosage, please contact the Diabetes Nursing Team well in advance of the appointment, to discuss appropriate measures.

Carrying Glucose to treat Hypoglycaemia 

On the day before and day of the procedure carry glucose tablets in case of hypoglycaemia. As these are absorbed quickly through the tissues of the mouth, if sucked, they will not interfere with the procedure. Take three (3) tablets initially, followed by a further three (3) after 10 minutes if symptoms persist. If your medication has been adjusted this should not be a problem.

Colonoscopy the procedure explained

How long will I be in the endoscopy department?

This largely depends on how quickly you recover from the sedation and how busy the department is. You should expect to be in the department for approximately 3 hours. 

The department also looks after emergencies and these can take priority over our outpatient lists.

What happens when I arrive?

When you arrive in the department, you will be met by a qualified nurse or health care assistant who will ask you a few questions, one of which concerns your arrangements for getting home. You will also be able to ask further questions about the investigation.

The nurse will ensure you understand the procedure and discuss any outstanding concerns or questions you may have. As you will be having sedation a small cannula maybe inserted (small plastic tube) in the back of your hand through which sedation will be administered later

As you will have sedation you will not be permitted to drive or use public transport so you must arrange for a family member or friend to collect you. The nurse will need to be given their telephone number so that we can contact them when you are ready for discharge.

You will have a brief medical assessment when a qualified endoscopy nurse will ask you some questions regarding your medical condition and any surgery or illnesses you have had to confirm that you are fit to undergo the investigation.

Your blood pressure and heart rate will be recorded and if you are diabetic, your blood glucose level will also be recorded. Should you suffer from breathing problems a recording of your oxygen levels will be taken. 

If you have not already done so, and you are happy to proceed, you will be asked to sign your consent form at this point.

Intravenous sedation 

The sedation and a painkiller will be administered into a vein in your hand or arm which will make you slightly drowsy and relaxed but not unconscious. You will be in a state called cooperative sedation. This means that, although drowsy, you will still hear what is said to you and therefore will be able to follow simple instructions during the investigation. Sedation makes it unlikely that you will remember anything about the examination. 

Whilst you are sedated, we will monitor your breathing and heart rate so changes will be noted and dealt with accordingly. For this reason you will be connected by a finger probe to a pulse oximeter which measures your oxygen levels and heart rate during the procedure. Your blood pressure may also be recorded. 

Please note as you have had sedation you must not drive, take alcohol, operate heavy machinery or sign any legally binding documents for 24 hours following the procedure and you will need someone to accompany you home.

The colonoscopy investigation 

In turn you will be escorted into the procedure room where the endoscopist and the nurses will introduce themselves and you will have the opportunity to ask any final questions. 

The nurse looking after you will ask you to lie on your left side and will then place the oxygen monitoring probe on your finger. The sedative drugs will be administered into a cannula (tube) in your vein. 

The colonoscopy involves manoeuvring the colonoscope around the entire length of your large bowel. There are some bends that naturally occur in the bowel and negotiating these may be uncomfortable for a short period of time but the sedation and analgesia will minimise any discomfort. 

CO2 or Air is gently passed into the bowel during the investigation to facilitate the passage of the colonoscope. 

During the procedure samples may be taken from the lining of your bowel for analysis in our laboratories. These will be retained.