Preparing for your colonoscopy

Before you go in for your colonoscopy, your bowel needs to be flushed clean so the doctor can see the inside of your colon clearly. You need to start your preparation 5 days before your procedure.

On this page

Important information

Read the information on this page at least 5 days before your procedure.

It is very important you follow all these instructions carefully. By the time you go in for your colonoscopy, the only thing remaining in your bowel should be clear or yellow to greenish fluid.

It is essential you drink the extra fluids explained in the steps below. Fluids prevent dehydration and are an important part of the cleansing process.

You must drink all the Glycoprep-C provided, even if you think your bowel is clear after only drinking some of it.

Remember to stay near a toilet after taking the Glycoprep-C, as you will experience diarrhoea. Individual responses to laxatives vary and they may work within 30 minutes or take up to 3 hours.

If you are regularly troubled by constipation, please tell us.

Medicines

  • If you are taking iron tablets, stop 10 days before your procedure.
  • If you are taking stool-bulking agents such as Metamucil or Normacol, stop 10 days prior to your procedure.
  • If you are taking blood thinning medicines such as aspirin, warfarin, dabigatran (Pradaxa), clopidogrel (Plavix), or dipyridamole (Persantin), and we have not given you information about stopping, contact us as soon as possible.
  • Continue to take all other medicines as prescribed by your healthcare provider.
  • If you have diabetes, read the additional preparation information at the bottom of this page.

Tips for taking Glycoprep-C

  • If you feel bloated, try a short walk.
  • If you feel cold or shivery, wrap up warmly.
  • If you feel nauseated, have a break or slow down drinking the Glycoprep-C.
  • Cleaning your teeth and tongue may help with nausea, or using a straw.
  • One or two barley sugar sweets may help with the taste.
  • You may get a sore anus due to going to the toilet so often. You can apply Vaseline to your anal area before starting Glycoprep-C to minimise this.

Where to go on the day

On the day of your appointment, come to the day stay unit, on the second floor of the Clinical Services Building on Pukeroa Street.

Rotorua Hospital mapPDF291 KB

Phone the booking office on 07 343 7742 if you have any problems with the preparation or you can't make your appointment.

Preparation steps

5 days before your admission

  • start low fibre diet
  • take your regular medicines
  • avoid eating nuts and food with seeds or skins, such as tomato, kiwifruit, corn, and grainy breads
  • do not drink red or purple drinks until after your procedure.

Low fibre diet guide (external link)

4 days before your admission

As above

3 days before your admission

As above

2 days before your admission

  • as above
  • drink plenty of fluids

One day before your admission

  • You may have a low fibre breakfast, then take 2 Bisacodyl laxative tablets with a large glass of water.
  • Eat an early light lunch. Do not eat after 12 noon (midday). Your next meal will be after your procedure.
  • Drink at least 10 glasses of clear fluids during the day (such as water, tea or coffee with NO MILK, light coloured fizzy drinks such as lemonade and ginger ale, cordial, Lucozade). After midnight you can continue to drink water.
  • Take your regular medications 1.5 hours (90 minutes) prior to beginning Glycoprep-C, or 1.5 hours (90 minutes) after completing it, to ensure they are absorbed.
  • For people with diabetes on metformin, vildagliptin, Galvus or Galvumet, do not take the evening dose.
  • Disregard the instructions on the Glycoprep-C packets. Dissolve the contents of each packet of Glycoprep-C in one litre of tap water, making a total of 3 litres. Refrigerate all 3 litres if you wish. You may add a cordial to flavour it such as lemon or lime, but do not use a red or purple cordial.
  • At 4pm, start drinking 2 litres of the Glycoprep-C solution. You should drink a glass every 5 to 10 minutes aiming to complete 2 litres in 2 hours. It is important that you drink all 2 litres of Glycoprep-C.

Day of procedure

  • NO FOOD ALLOWED
  • For a morning admission, you must drink the third litre of Glycoprep-C between 4am and 5am.
  • For an afternoon admission, you must take the third litre of Glycoprep-C between 9am and 10am.
  • Continue drinking water up until one hour before your admission to hospital to prevent dehydration.
  • Take regular medicine with a small amount of water.
  • Do not take your diabetes medicine or insulin unless you have been advised to do so. Bring it with you to the hospital.
  • On admission, tell us if you are taking sleeping tablets, steroids, opioids, or immunosuppressants.
  • If you have obstructive sleep apnoea (OSA), bring your CPAP machine.

After your procedure

  • Discharge time is generally 2 to 4 four hours after your admission.
  • Because you are given sedation, you cannot drive afterwards. You must have a responsible adult to collect you from the day stay unit and take you home. They should remain with you for the rest of the day.
  • You cannot wait outside for your transport, catch a taxi, or take a bus alone.

 

Extra information for people with diabetes having a colonoscopy

If you have diabetes, the steps above apply to you, but there is additional information you need.

If you have any questions about controlling your diabetes whilst preparing for your colonoscopy, contact your diabetes care team or the endoscopy unit.

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Long acting insulin

If you are taking Lantus, Levemir, Protaphane or Humulin NPH:

  • 2 days before procedure — take the usual dose
  • day before procedure — take half the usual morning and half the afternoon dose
  • day of procedure — take half the usual morning dose
  • resume the usual afternoon dose after the procedure, when you are eating normally.

Mixed insulin

If you are taking HumalogMix25, HumalogMix50, Novomix30 or Penmix30

  • 2 days before procedure — take the usual dose
  • day before procedure — take half your usual morning dose and half your usual afternoon dose
  • day of the procedure — take half your usual morning dose
  • resume your usual afternoon dose after the procedure, when you are eating normally.

Rapid acting insulin (taken with meals)

If you are taking Novorapid, Humalog, Apidra or Actrapid:

  • 2 days before procedure — take the usual dose(s)
  • day before procedure — do not take 
  • day of procedure — DO NOT TAKE DOSE AT BREAKFAST
  • check blood glucose level every 4 hours. If your blood glucose is above 11mmol/L you may use a correcting dose of rapid-acting insulin (if this has been prescribed).
  • resume your usual dose after the procedure, once you are eating and drinking normally.

Metformin and Galvumet:

  • Day before the procedure — do not take the evening dose
  • Miss the dose the day of the procedure.
  • Resume tablets the day after the procedure.

Vildagliptin and Galvus:

  • Day before the procedure — do not take the evening dose
  • Miss the day of the procedure.
  • Resume tablets the day after the procedure.

Empagliflozin, Jardiance or Jardiamet:

  • Stop 3 days before the procedure
  • Miss the day of the procedure.
  • Resume tablets the day after the procedure.

Gliclazide, Glipizide or Glibenclamide:

  • Miss the morning and afternoon dose the day before the procedure.
  • Miss the morning dose on the day of your procedure.
  • Resume tablets in the afternoon if eating and drinking normally

Pioglitazone:

  • Miss the morning of the procedure.
  • Resume tablets the day after the procedure.

If you are taking dulaglutide (Trulicity) or liraglutide (Victoza)

  • Miss the morning of the procedure
  • Resume injections the day after the procedure

Contacts for people with diabetes

Diabetes nurse specialists:

Rotorua:

Taupo:

Endoscopy clinical nurse coordinator:

Your consent

Before a doctor or healthcare professional examines or treats you, they need to gain your consent in writing. If you later change your mind, you are entitled to withdraw consent, even after signing.

The endoscopist or health professional will ensure you have enough information about the colonoscopy to enable you to decide whether to have the procedure. They will write this information on the consent form. 

You are encouraged to ask questions and inform us of any concerns you may have. It may be helpful for you to write these down as a reminder.

This is your decision. It is up to you to choose whether or not to consent to what is being proposed. Ask as many questions as you like and express any concerns about medicines, allergies or past medical history.