This leaflet is for anyone with diabetes (of any type) who is due to have an endoscopy.

This covers:

  • gastroscopy
  • transnasal gastroscopy
  • sigmoidoscopy without bowel preparation
  • ERCP.

Bowel preparation (or ‘Bowel prep’) means completely emptying the bowel before a procedure. This is not needed for procedures that only involve inspection via the mouth or nose.

Follow what applies to you

Here we cover how to alter your insulin or other diabetes medication around the time of your appointment to control your blood sugar safely.

Follow what applies to you:

  • Instructions for those on insulin
  • Instructions for those on medications other than insulin

If you control your diabetes with diet alone, you do not need to do anything apart from the bowel preparation instructions you have been sent.

Remember

  • Tell the endoscopy team that you have diabetes. We can then give you an appointment as close to the start of the morning or afternoon as possible. This is to reduce any disruption to your usual insulin or medication regimen.
  • On the day before and the day of the procedure carry glucose tablets in case of low blood sugar levels. If your blood sugar levels drop (less than 4 mmol/l), see the hypoglycaemia instructions at the end of this document.
    If you have had a ‘hypo’ and taken glucose, tell the nurses when you arrive.
  • If you usually check your blood sugar levels yourself, you should continue to do so, particularly before taking insulin. If you do not usually check them, we will do so when you arrive.

Instructions for those on insulin

What insulin are you on?

Novomix 30
Humalog Mix25 or Mix50
Humulin M3
Day before
  • No change.
Day of the appointment

  • Take half your usual morning insulin dose with a light breakfast 6 hours before appointment.

  • Take your usual insulin dose in the evening.

Novorapid
Humalog
Apidra
Day before

  • No change.

Day of the appointment

  • Morning appointment (before 12.30):

    • Do not take your morning insulin.

    • Start taking your usual doses when you start eating and drinking again.
       

  • Afternoon appointment (after 12.30):

    • Take your usual morning insulin but not your lunchtime dose.

    • Start taking your usual doses again with evening meal.

Insulatard

Humulin I

Levemir (detemir)

Lantus (glargine)

Toujeo

Tresiba
Day before

  • If you have your insulin in the morning, no change.

  • If you have your insulin in the evening, reduce the dose by 20%.

    To work out your reduced dose, times your usual dose by 0.8 

Day of appointment

  • If you have your insulin in the morning, reduce the dose by 20%.

    To work out your reduced dose, times your usual dose by 0.8 .
     

  • If you have your insulin in the evening, no change.
Day before
  • No change.
Day of appointment
  • No change.

Instructions for those on medications other than insulin

What diabetes medication are you on?

metformin
sitagliptin
saxagliptin
linagliptin
repaglinide
pioglitazone
dapagliflozin
empagliflozin
acarbose

Morning appointment (before 12.30):

  • Do not take your morning dose.
  • If you are able to eat lunch, take your usual lunchtime dose PLUS half your breakfast dose at the same time.

Afternoon appointment (after 12.30):

  • Take your morning dose with breakfast.
  • Do not take your lunchtime dose.
  • Start taking your medication as normal when you start eating and drinking as usual.

gliclazide
glimepiride
tolbutamide
glibenclamide

Morning appointment (before 12.30):

  • Do not take your morning dose.
  • If you are able to eat lunch, take your usual lunchtime dose PLUS half your breakfast dose at the same time.

Afternoon appointment (after 12.30):

  • Do not take morning OR lunchtime doses.
  • Start taking your medication as normal when you start eating and drinking as usual.

exenatide

liraglutide (Saxenda, Victoza)

dulaglutide (Trulicity)

Bydureon

semaglutide (Ozempic)

Xultophy

lixisenatide

Morning appointment (before 12.30):

  • Take your dose as normal.


Afternoon appointment (after 12.30):

  • Take your dose as normal.

General advice

Contact for advice

For advice about insulin dose adjustments, contact the diabetes nurse team on 020 8934 6370.

Avoiding low blood sugars

  • Check your blood glucose regularly.
    If it drops below 4 mmol/l, have approximately 20g carbohydrate (see Box 1) until your blood glucose is back above 5. You can do this for up to 4 hours before your appointment.
     
  • To avoid the risk of low blood sugars, you can have sips of water and/or sips containing carbohydrates until 2 hours before your appointment. 
    See Box 1 for examples.

Box 1

For approx. 20g carbohydrates

  • 200ml (13 tablespoons) of non-diet cola 
    OR
  • 4 teaspoons of sugar in 100ml of water
    OR
  • 200ml clear apple/grape juice
    OR
  • 220ml Lucozade
    OR
  • 5 or 6 glucose tablets

Hypoglycaemia

  • If you have a hypo (hypoglycaemia) during the 4 hours before your appointment, follow the advice in Box 2.

    Tell the endoscopy department if this happens.
     
  • If your blood glucose does drop below 4 and/or you take glucose, let the endoscopy nurses know when you arrive, or call us if you think that it will be difficult to come for your appointment. 

Box 2

Hypo treatment

Step 1

Take 15 to 20g rapid-acting glucose:

  • 5 to 6 dextrose/Lucozade sweets
    OR
  • 5 to 6 Glucotabs
    OR
  • 150ml to 200ml fruit juice or non-diet cola
    OR
  • one 60ml bottle Glucojuice (Lift)

Step 2

  • Test glucose after 10 minutes
  • Repeat step 1 if still below 4.0mmol/L

Contact information

Endoscopy nurses helpline
020 8934 6614 (2pm to 4pm only)

Diabetes nurses
020 8934 6370