How to Make Your Colonoscopy Prep “Not Suck”


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For decades, the saying, “It’s the prep, not the procedure” has pretty well summed up the ills of the colonoscopy prep experience. The complaints have always centered around three issues: taste of the laxatives, unintended side effects (nausea, vomiting, bloating, and cramping), and hunger from fasting. 

Golytely® first came on the GI scene over 40 years ago as one of the early prescription preps. That same year Jimmy Carter was the president, the average cost of a new car was $7200, and millions of people tuned in to see who shot JR Ewing. While the world has changed dramatically, colon preps have not and remain a substantial barrier to many patients considering colonoscopy.  

In a review of 58 studies with nearly 25,000 patients, the leading cause of anxiety related to colonoscopy was the bowel preparation1. Many a patient either declines or cancels their colonoscopy due to what they heard or experienced with colonoscopy preps.  

So as a patient: "Do I have any choices in how I prep to make the experience easier?" The good news is emphatically, "YES!" But to be your own advocate, you need some basic information about colonoscopy preps and a behind-the-scenes look at the colonoscopy scheduling process.  

One of the first questions to consider is what types of laxatives are available and what are some of the differences in effectiveness and tolerability? Colonoscopy preps can be divided into some different categories but for our discussions let’s just look at Over the Counter (OTC) versus prescription preps.    

Prescription preps have been FDA approved for colonoscopy preparation. Prescription preps are generally effective and tolerable in most patients. However, due to the sometimes high cost, bad taste, and side effects of prescription preps, GI doctors have also used OTC preps for many years as an alternative. OTC preps use combinations of laxatives indicated for constipation such as MiraLAX®, Dulcolax®, Senna and Magnesium Citrate. While not FDA approved, OTC preps have been used extensively and found to have similar safety profiles and success rates, making them a community standard in most areas.  

A large real-world study comparing preps was performed at Cedars-Sinai Medical Center which included 4,339 patients and 75 different doctors2. They allowed doctors to use their regular preps (64% OTC versus 36% prescription) and compared bowel cleansing and tolerability. They found that the OTC and prescription preps performed similarly with respect to cleansing and tolerability, except for Golytely®, which was worse. Failure rates were comparable at around 8% for all preps, again except for Golytely®. In other words, almost all the preps tested performed fairly well and with similar results so there was no definitive “best” prep. 

Most patients think the prep was specifically chosen for them by their doctor. The actual truth is most patient’s preps are chosen by the scheduler from a list of OTC and prescription preps OK’d by the doctor. Schedulers are either medical assistants or nurses that are typically office-based. Unfortunately, because they are primarily in the office, they do not get much exposure to the actual colonoscopy experience. They also do not get to hear the patient’s prep stories, and if they had any significant difficulties. Because of these factors, schedulers may choose colon preps based on some misperceptions.  

One of the most common misperceptions is the cost of the prep. Rightfully so, many schedulers tend to be very cost-conscious and frequently use that to choose preps. Schedulers are commonly informed by industry reps that a prescription prep is “covered” by insurance. This can be easily misunderstood to mean the prep has “no cost” to the patient. What this means is insurance pays a portion of the cost, but the patients typically have a copay, and it is almost impossible to know what that amount is until the patient is at the pharmacy. In a quality improvement project for our office, we asked 500 patients with insurance what was their copay, or out-of-pocket expense, for their prescription prep. We found that patient copays ranged widely from $0-$165, with an average copay of $72 for their prescription prep. So “covered” does not mean free. 

Lastly, colonoscopy patients have routinely fasted with only clear liquid diets for 24-48 hours before the procedure. This causes extreme hunger, fatigue and in some populations, blood sugar issues and an ill feeling. While it is counterintuitive, we have known for quite some time that patients could eat a low residue diet while prepping. A meta-analysis of 20 different studies involving 4,300 patients compared clear liquid diet to low-residue diet on the prep day3. They found that the patients eating a low-residue diet had a comparable cleanse to clear liquid diet, with higher patient compliance and satisfaction scores. However, it has been difficult to incorporate into prep directions without confusing patients, and so most practices still use very restrictive diets.  

An observational study was performed with 546 patients looking at the performance characteristics of a low-residue food kit coupled with OTC laxatives for colonoscopy preparation4. The kit contained three small meals, three snacks, flavored electrolyte drink mixes, and the laxatives. The laxatives were dosed in a unique, intermittent-dosing schedule where the patient ingested small doses of laxatives with their meals, snacks, and drinks, instead of the traditional single or split dosing. The colonoscopy prep success rate was 98% (BBPS of 6 or >) and the average quality of cleanse was also excellent at BBPS of 8 (perfect score = 9). Patient satisfaction scores with high, as was compliance. The intermittent dosing schedule of the tasteless laxatives was thought to markedly reduce the frequent unwanted side effects often associated with other preps. 

There are some special considerations when picking a prep. If you have issues with chronic severe constipation, are significantly overweight, are on multiple medications, have renal failure or have failed a previous prep, then you need to have a discussion with the GI office and alter your colon prep appropriately. 

So, what can you do to take charge of your prep experience? Know that you have a choice of preps. All colon preps can clean your colon, but it is frequently how well you tolerate the prep that makes the difference. Look at or Google reviews to see how other patients describe the taste of the prep, did they have any unwanted side effects and comparisons of the costs. Talk to your doctor about following a low-residue diet the day you’re prepping, to make the day more pleasant as well as making it easier to drink more fluids. There also may be a better dosing schedule that alleviates the side effects and improves the quality of your cleanse. Be your own advocate! 

For more information, please visit or call 855-423-6637, and we would be happy to visit with you. 

1Yang, Chengyue, et al. “Anxiety Associated with Colonoscopy and Flexible Sigmoidoscopy: A Systematic Review.” American Journal of Gastroenterology, vol. 113, no. 12, Dec. 2018, pp. 1810-1818., doi:10.1038/s41395-018-0398-8. 

2Gu, Phillip, et al. “Comparing the Real World Effectiveness of Competing Colonoscopy Bowel Preparations: Results of a Prospective Trial.” The American Journal of Gastroenterology, vol. 152, no. 5, Feb. 2017, pp. 305-314., doi:10.1016/s0016-5085(17)31937-6. 

3Zhang, Xubing, et al. “Low Residue Diet Versus Clear-Liquid Diet for Bowel Preparation before Colonoscopy: Meta-Analysis and Trial Sequential Analysis of Randomized Controlled Trials.” Gastrointestinal Endoscopy, vol. 92, no. 3, 2020, pp. 508-518. 

4Scott, Jeffery, et al. “PEG 3350, Senna and Solid Food Based Bowel Preparation for Colonoscopy Appears Safe, Effective and Well Tolerated”. EC Gastroenterology and Digestive System 4.5 (2017): 142-151. 

One thought on “How to Make Your Colonoscopy Prep “Not Suck”

  1. I’ve had multiple failed preps with both a 1 day split prep using SuPrep and a 2 day prep using a combo of Miralax + Dulcolax and SuPrep (split). In both cases i had a week of low fiber diet and then liquid only diet during the prep. I feel like I need to advocate for myself in the next attempt but not sure what would help. What would you recommend?

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