Bowel preparation before a colonoscopy is critical. Prep starts days before, when you stop taking certain medications and eating high-fiber foods. You must follow your provider’s instructions exactly to avoid last-minute cancellations.
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Golytely, Nulytely, Trilyte, and Colyte are brand names for a medication called polyethylene glycol 3350 with electrolytes. These medications clean out your colon (large intestine) to prepare it for a colonoscopy. They work by softening your poop (stool) so it’s easy to have a bowel movement. The electrolytes in the mixture help prevent dehydration.
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Preparing for a colonoscopy with a bowel preparation kit is essential. It completely empties your colon of stool. This gives your gastroenterologist the clearest view of the lining of your colon so they can identify polyps or cancer. When your colon isn’t completely clear, they can’t identify problems, and your colonoscopy results may not be accurate. For your doctor, a clean colon is like driving on a clear, sunny day. A dirty colon is like driving in a rainstorm.
Golytely, Nulytely, Trilyte and Colyte come as powder solutions in a large jug. The day before your colonoscopy, you’ll add a specific amount of water to the jug. Be sure to follow the instructions on the label carefully.
Once you add water to the solution, it creates a laxative that you drink. Your colon should be clear by the time you finish drinking the entire jug (if you followed all the instructions correctly).
If you’re a Cleveland Clinic patient, you must follow the instructions for bowel preparation exactly as prescribed or your colonoscopy will be canceled.
The following instructions are key to a successful colonoscopy:
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A responsible adult driver must be with you when you check in before your colonoscopy. They must stay in the waiting area until you’re discharged. You’re not allowed to leave alone after your colonoscopy. If you don’t have a driver with you to take you home, your exam will be canceled.
For your safety, certain medications will need to be stopped or adjusted before you can have your procedure. These include:
Medications like aspirin, antibiotics or diuretics should be taken the day of the exam with a sip of water.
If you’re unsure about which medications you can continue to take, please contact your healthcare provider.
Stop eating these high-fiber foods three days before your colonoscopy:
You should only drink clear liquids beginning the day before your colonoscopy. Don’t eat any solid foods.
You can continue to drink clear liquids until three hours before your colonoscopy. The table below shows what you can and can’t drink:
OK to Drink (No Red, Purple or Orange Liquids) | DO NOT DRINK |
---|---|
Gatorade or Powerade in yellow, green or blue | Alcohol |
Clear broth or bouillon | Milk or non-dairy creamer |
Coffee or tea (no milk or creamer. Sugar and sugar substitutes are OK) | Noodles or vegetables in broth |
Sodas/soft drinks | Juice with pulp |
Kool-Aid or other fruit-flavored drinks in yellow, green or blue | Liquid you can’t see through |
Strained fruit juices (no pulp) | |
Jell-O, Popsicles, hard candy (not red, purple or orange) | |
Water | |
OK to Drink (No Red, Purple or Orange Liquids) | |
Gatorade or Powerade in yellow, green or blue | |
DO NOT DRINK | |
Alcohol | |
Clear broth or bouillon | |
DO NOT DRINK | |
Milk or non-dairy creamer | |
Coffee or tea (no milk or creamer. Sugar and sugar substitutes are OK) | |
DO NOT DRINK | |
Noodles or vegetables in broth | |
Sodas/soft drinks | |
DO NOT DRINK | |
Juice with pulp | |
Kool-Aid or other fruit-flavored drinks in yellow, green or blue | |
DO NOT DRINK | |
Liquid you can’t see through | |
Strained fruit juices (no pulp) | |
DO NOT DRINK | |
Jell-O, Popsicles, hard candy (not red, purple or orange) | |
DO NOT DRINK | |
Water | |
DO NOT DRINK | |
Note: Brand names are registered trademarks.
Mix the solution the afternoon before your colonoscopy and refrigerate it before drinking. You may add the flavor pack that came with the bowel preparation. Don’t add ice, sugar or any other flavorings to the solution.
You’ll drink the bowel preparation solution in two parts:
Part 1: 6:00 pm the evening before your colonoscopy
Part 2: Six hours before your colonoscopy
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Some people's bowels move slowly, and they may need different instructions. Please see your doctor for personalized bowel prep instructions if you have:
Bowel prep with polyethylene glycol is safe and effective, but it can cause side effects. Some of those are:
You may take extra laxatives in the days leading up to your prep. This should help resolve your constipation before your bowel prep day.
Contact your physician as you’ll likely need additional bowel prep instructions.
Certain medical conditions and medications can slow bowel emptying or lead to constipation. Conditions like Parkinson’s, multiple sclerosis (MS) or using a wheelchair can slow down your digestion. Medications like narcotics, gabapentin and anticholinergic medications can also have an impact. Contact your physician and be sure to share your medical history and current medication use, as you’ll likely need extra time and additional laxatives to complete your bowel prep.
Start your prep two to three hours earlier to allow yourself more time to complete the entire prep.
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If you can’t finish your entire bowel prep, you’ll likely need to reschedule your colonoscopy due to poor prep quality.
Gastric bypass surgery involves your stomach and small bowel. It doesn’t change the length of your colon. You may need to drink smaller amounts, more slowly. You’ll need to complete the entire bowel prep, it may just take longer time to complete it.
Please consult your nephrologist before scheduling to get instructions that are specific to you. In general, dialysis patients take the Golytely bowel prep and have the procedure on the same day as their dialysis (colonoscopy in AM, dialysis in PM).
If you can pour it in a glass and you can see through it, it’s considered "clear liquid."
An adult must be present with you at check-in for your colonoscopy and remain in the endoscopy area until you’re discharged. You can hire a driver to take you home only if this adult escort is with you at check-in, remains in the endoscopy area until you’re discharged, and takes the hired ride home with you.
No, you must have an adult with you when you check in. Your responsible adult must remain in the endoscopy center during your procedure and then drive you home. You can’t drive a vehicle after your procedure for the rest of the day.
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Preparing for your colonoscopy with bowel prep is key to a successful exam. Your provider can better detect polyps and other problems when your colon is completely clear. The directions vary depending on the type and brand of bowel prep you use, and from facility to facility. Don’t hesitate to contact your healthcare provider if you have questions about how and when to drink the prep mixture. Not following your healthcare provider’s instructions could result in your colonoscopy being canceled.
Last reviewed on 04/22/2025.
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