The guidelines below will help you adjust your diabetes medicine and diet as you get ready for your test.
If you see a diabetes educator or diabetes specialist, contact them at least 1 week before your test to ask about adjusting your diabetes medicine or insulin.
Diet
- Follow the instructions the gastroenterology (GI) clinic gives you about what you can eat or drink before the test.
-
If your test is in the morning, don’t eat or drink anything after midnight.
-
If your test is in the afternoon, you can only have clear fluids in List 1 or 2 (below) until 4 hours before the test.
- If your blood sugar drops below 4.0 mmol/L or if you have symptoms of low blood sugar, take 15 grams of a carbohydrate-containing fluid from List 1. Test your blood sugar again in 15 minutes. If your blood sugar is still low, take another 15 grams of carbohydrate-containing fluid from List 1.
| List 1 - Fluids that have sugar (Each has about 15 grams of carbohydrates) | List 2 - Fluids that aresugar-free (Choose as desired) |
- Black tea, coffee, or water with 1 rounded tablespoon (15 mL) sugar or honey
- ½ cup (125 mL) regular Jell-O®
- ½ cup (125 mL) regular (sugar sweetened) Kool-Aid®
- ¾ cup (175 mL) fruit drink or fruit juice without pulp (e.g., apple, white grape)
- ¾ cup (175 mL) regular pop
- 1 cup (250 mL) sports drinks (e.g., Gatorade®)
| - Water
- Clear bouillon, broth, or consommé
- Diet pop
- Diet Kool-Aid® or Crystal-Lite®
- Black coffee or tea
- Diet popsicle
- Diet Jell-O®
|
Testing your blood sugar
Test your blood sugar anytime you feel your blood sugar is low or high.
- Test your blood sugar at least every 4 hours. Blood sugars in the range of 8.0 to 12.0 mmol/L are fine for these 2 days, even if it’s higher than your usual target.
- If you have type 1 diabetes or you are on an SGLT2 inhibitor, like canagliflozin (Invokana), dapagliflozin (Forxiga), empagliflozin (Jardiance) and ertugliflozin (Steglatro) and your sugars are over
14.0 mmol/L, test your urine or blood for ketones.
- If you have Type 1 diabetes and are positive for ketones, you may need extra insulin. Moderate to large ketones may mean that you’re in DKA (diabetic ketoacidosis) and need to go to the Emergency Department right away.
- If you’re worried about your blood sugar level, speak with your healthcare provider or diabetes educator.
Adjusting your diabetes medicine
If you take insulin
The day before your test
- All doses stay the same at breakfast, lunch and supper.
Evening/Bedtime
-
Basal Insulin: Reduce your dose of basal insulin (Humulin N, Novolin NPH, Lantus, Basaglar, Toujeo, Levemir or Tresiba) by 20% or the amount your healthcare provider tells you.
Tresiba may need to be reduced for 2-3 days before the procedure. Talk with your healthcare provider.
Your dose will be
units. -
Insulin Pump: You may need to reduce your basal rate by 10% to 20% overnight if there are concerns about low blood sugar. If there are no concerns, keep the same basal rate.
Test day
Morning
-
Bolus (meal) Insulin: Don’t take your morning bolus (meal) insulin (Apidra, Humalog, NovoRapid, Fiasp, Humulin R, or Novolin Toronto).
-
Premix Insulin: Don’t take your morning premix insulin (Humulin 30/70, Novolin 30/70, or
Humalog 25/75).
-
Basal Insulin: Reduce your dose of basal insulin (Humulin N, Novolin NPH, Lantus, Basaglar, Toujeo, Levemir or Tresiba) by 20% or the amount your healthcare provider tells you.
Tresiba may need to be reduced for 2-3 days before the procedure. Talk with your healthcare provider.
Your dose will be
units. -
Insulin Pump: You may need to reduce your basal rate by 10% to 20% if there are concerns about low blood sugar. If there are no concerns, keep the same basal rate.
*Be sure to bring a source of fast-acting sugar and your blood glucose meter with you.
After the test
-
Premix Insulin: Reduce your morning dose of premix insulin (Humulin 30/70, Novolin 30/70 or
Humalog 25/75) by 20% (or the amount your healthcare provider tells you) for your first meal after the test. Your dose will be ______________ units.
-
All other insulin: Take as prescribed.
If you take diabetes medicine other than insulin
The day before your test
- Take your medicine as normal or as your healthcare provider tells you.
Test day
- Don’t take any diabetes medicine until after your test is done and you’re eating. Then take it as per your scheduled dose.
*Be sure to bring a source of fast-acting sugar and your blood glucose meter with you.
For 24/7 nurse advice and general health information call Health Link at 811.
