Preparing for Your Colonoscopy with Polyethylene Glycol 3350/MiraLAX and Bisacodyl/Dulcolax
Preparation instructions for your upcoming colonoscopy with Polyethylene Glycol (PEG) 3350/MiraLAX and Bisacodyl/Dulcolax.
Questions after reading this?
Call the GI Triage Line at 720-723-6166, option 2, Monday – Friday and leave a message. An RN will call you back within 48 hours, or on Monday if you call on the weekend. For questions at night or on weekends, call 303-399-8020, select “0” and ask for the GI doctor on call.
As soon as you schedule your colonoscopy
- Please arrive 60 minutes before your appointment time. Expect to be here, from check to discharge, for up to four (4) hours.
- For all procedures involving Sedation/Anesthesia:
For your safety, an adult should accompany you home after procedures with sedation. The adult can drive you home or accompany you on public transportation. No Uber/Lyft, taxi, bus or any other form of public transportation can be used if you are alone after sedation. There are a few options that can be arranged prior to your procedure if you do not have an adult to assist you. If there are safety concerns, your procedure will be canceled.
Prep Medications
- If you are missing your prep medications, please call the outpatient pharmacy at
choose option 1 – option 3 to request a refill. You will need to provide: - Name/Last 4 of SSN
- Date of procedure
- Prep medication name or Type of procedure
- And, if able to pick up at RMR VA Outpatient pharmacy window
14 days before your colonoscopy
- If you haven't received a bottle of Polyethylene glycol (PEG) 3350/MiraLAX and four tablets of Bisacodyl/Dulcolax in the mail, call the GI Triage Line at 720-723-6166.
- The Anticoagulant Clinic should call you if you take a blood thinner such as Warfarin/Coumadin, Eliquis/Apixaban, Xarelto/Rivaroxaban or Pradaxa/Dabigatran. If they haven’t by fourteen days prior to the procedure, call 720-723-6756.
- If you are on Plavix/Clopidogrel, Brilinta/Ticagrelor, Pletal/Cilostazol, Aggrenox/Aspirin with Dipyridamole or Prasugrel/Effient, you should receive a call from the GI Department at least fourteen days prior to the procedure. If you don’t, please call 720-723-6166.
7 days before your colonoscopy
- STOP EATING corn, popcorn, frozen corn, seeds or nuts of any type. These foods are very difficult to clean from your colon.
- STOP taking any IRON supplements as they interfere with good bowel cleansing.
- Buy two 32-ounce size bottles of Gatorade, but NO purple, red or orange colored flavors.
3 days before your colonoscopy
- STOP taking any Vitamin E, fish oil, mineral oil, or flaxseed oil. These can cause bleeding.
2 days before your colonoscopy
- For breakfast and lunch, eat as you normally would.
- For dinner, eat ONLY a SMALL, LIGHT meal. This is the last solid food you will have until after your colonoscopy. Drink only clear liquids the rest of the night.
The day before your colonoscopy
- No solid foods today!
- Drink ONLY clear liquids (liquids you can see through) such as Gatorade, soft drinks, clear juices (without pulp), Kool-Aid, Jell-O, popsicles, clear broth, black coffee or tea. Drink lots of clear liquids to stay hydrated! The prep will work much better if you are.
- DO NOT DRINK milk or dairy products, alcohol, beer, or any clear liquid or Jell-O that is red, orange, or purple in color. These dyes are difficult for the doctor to see through.
- At 3 p.m., swallow FOUR Dulcolax/bisacodyl tablets with at least 16 ounces of a clear liquid.
- At 5 p.m., mix 1/2 (one half) of the bottle of PEG 3350/MiraLAX (about 119 grams) in one of the bottles of Gatorade. Shake it well to dissolve.
- You may use warm, cold or room-temperature Gatorade. Some patients find drinking the prep through a straw helpful.
- Finish this solution WITHIN 1 HOUR by drinking an 8-ounce glass every 10 to 15 minutes until you finish the bottle.
- PEG 3350/MiraLAX is a laxative. It empties your colon, so the doctor will be able to see its walls and spot any abnormal growths (polyps).
- PEG 3350/MiraLAX will give you diarrhea! This is normal.
- You may drink other clear liquids after you finish the PEG 3350/MiraLAX and Gatorade, up until midnight.
- After midnight DON’T drink anything except what we instruct you to further in these instructions!
TIP: You may want to buy flushable baby wipes and Vaseline to use during your prep due to skin irritation.
The day of your colonoscopy
- Do not eat any solid food today, and drink clear liquids only as instructed below!
- FIVE HOURS BEFORE LEAVING for your colonoscopy, mix the other 1/2 (one half) of the bottle of PEG 3350/MiraLAX (about 119 grams) in the other bottle of Gatorade and shake it well to dissolve.
- Drink an 8-ounce glass of the solution every 10 to 15 minutes until you finish it.
- Take any morning medications you need at least FOUR HOURS BEFORE your colonoscopy, with a few sips of water to swallow any pills, tablets or capsules.
- During the FOUR HOURS BEFORE your colonoscopy, for your own safety, there should be NOTHING IN YOUR MOUTH, not even chewing gum.
- If you have ANYTHING in those four hours, even WATER, your colonoscopy will be delayed or canceled.
- Your stool should be clear and yellow, with no solid particles in it.
- Come to your appointment 60 minutes beforehand! The GI Lab is on the 3rd floor of building D, Mount Harvard. Take elevator number 1 to the 3rd floor, and our waiting room will be on the east side of the building.
Do you have diabetes? Or take any weight loss/diet medication?
Take special care while only drinking clear liquids!
- Monitor your blood sugar every 4 hours during your prep time before your colonoscopy.
- If you have an insulin pump: Maintain pump as usual and bring all pump equipment and supplies as well as continuous glucose monitor on the day of the procedure.
Oral diabetic medications: Please hold all oral diabetic agents the morning of the procedure.
Metformin: Hold the night before and the day of the procedure.
GSLT2i: (Canagliflozin,Dapagliflozin,Empagliflozin): hold 3 days prior to the procedure.
GLP1R: agonists (Ozempic, Wegovy): Hold oral dose the morning of surgery. Hold weekly injections 1 week(7 days) prior to the procedure.
Insulin: Hold all short acting insulin when on the liquid diet (1- or 2-day colon prep). Decrease the long-acting Insulin 50% the days you are doing the prep/liquid diet. Take 50% of the normal long-acting dose of insulin on the day of the procedure IF YOU TAKE A MORNING DOSE.
Do Not Take short acting insulin on the days of prepping/liquid diet or day of the procedure.
Taking any of the following GLP-1 medications for Diabetes, weight loss, or any other reason? If taking once daily, stop taking 2 days before procedure. If taking once weekly, stop at least 7 days before procedure: Dulaglutide, Exenatide, Liraglutide, Lixisenatide, Semaglutide, Tirzepatide. Stop taking Phentermine 7 days before procedure.
Please consult your PCP or Endocrinologist if you think your diabetic or weight loss adjustment may be an issue for you.