ClearFast PreOp® Drinking Instructions
Whether it’s for a minor procedure, major surgery or alongside your colonoscopy prep drink, ClearFast is here for you. Find out when you should drink your bottles of ClearFast PreOp® with the drinking instructions below.
Surgeries & Procedures
1st Bottle:
Drink the night before your surgery
once you’re in the fasting window
2nd Bottle:
Drink 2 hours before your surgery
3rd Bottle:
Many patients choose to have a chilled
ClearFast following their surgery
Colonoscopy Prep
1st Bottle:
Sip simultaneously with your
colonoscopy prep drink; “Chase”
each sip of prep formula with
a sip of ClearFast
2nd Bottle:
Drink the night before your procedure
(once you’re in the fasting window)
3rd Bottle:
Drink 2 hours before your procedure
4th Bottle:
Many patients choose to have a chilled
ClearFast following their procedure
Children’s Procedures
1-3 years or 20-34 lbs (9-15 kgs):
Drink 4 ounces 2 hours prior to a surgery
4-8 years or 35-60 lbs (16-27 kgs):
Drink 6 ounces 2 hours prior to a surgery
9-12 years or 60-100 lbs (28-45 kgs):
Drink 8 ounces 2 hours prior to a surgery
13+ years – Standard Drinking Instructions
Drink 12oz of ClearFast 2 hours
prior to procedure
You can also try our Drinking Instructions Calculator!
1. From the list below, select the calculator that best fits your procedure
2. Enter the time your procedure is scheduled for
3. Email the schedule to yourself for easy reference
Always consult your physician about what is the appropriate timing for and amount
of ClearFast PreOp that you should be drinking, especially prior to surgery.
Type 1 Diabetic
With appropriate insulin administration, yields euglycemia.
1st Bottle:
Drink the night before your surgery
once you’re in the fasting window
2nd Bottle:
Drink 2 hours before your surgery
Patients simply “match their short-acting insulin
injections” to their blood glucose level and to the
carb load that is listed on the drink label.
Type 2 Diabetic
With preservation of their oral anti-hyperglycemic agent
schedule at bedtime.
1st Bottle
Drink the night before your surgery
once you’re in the fasting window
2nd Bottle
Drink 2 hours before your surgery
Morning dose of oral agent may be held based on the
actual surgical time, e.g., as when surgery is scheduled
as one of the first cases of the morning.