Comparison of Bowel Preps

full update December 2024

Inadequate bowel prep for colonoscopy is common (up to 25%) and can lead to cancelled procedures, missed detection and/or removal of polyps, prolonged duration of procedures, and other problems.1,2,d Providing written instructions for bowel preps may improve the quality of cleansing.3,4 Patients should avoid products (e.g., Gatorade, Popsicles, Jell-O, cranberry juice) with red or purple coloring or dyes due to interference with colonoscopy results (e.g., confused as blood).5,6 Use this chart to compare bowel preps and help improve adherence with colonoscopy bowel prep instructions.

Products/Costa

Adult Split Dosingc,g

Efficacy

Tolerability/Cautionsb,e

Polyethylene glycol (PEG) ELS: iso-osmotic, nonabsorbable electrolyte solution cleanses the intestinal lumen through catharsis.5

  • PEG with electrolytes is generally considered the gold standard despite being least tolerable.1 (PEG 2 L plus bisacodyl is preferred if unable to tolerate PEG 4 L.7)

Standard volume

(PEG 4 L)

US: GaviLyte, GoLytely, TriLyte (sulfate-free)

Canada: CoLyte, PegLyte

All: ~$20 to $25

Evening before:5 Reconstitute powder per labeling. Drink 2 L of prep
(~250 mL every 10 minutes).

Day of (4 to 6 hours before colonoscopy):5 drink the rest (~2 L), finishing 2 hours prior to colonoscopy.
  • PEG 4 L appears equally effective to:
    • low-volume PEG and PEG 2 L plus bisacodyl tabs
      (10 mg).1,4,9-16
    • sodium phosphate (US)17
  • PEG 4 L appears slightly more effective than PEG without eletrolytes.11,15,16
  • PEG 4 L may be slightly less effective than PEG 2 L plus magnesium citrate or sodium picosulfate, citric acid, and magnesium oxide.4,9,12,14
  • Using only ½ of the PEG 4 L plus oral bisacodyl is as effective as low-volume PEG products.14
  • Adding senna to lower volumes of PEG does NOT result in additional benefit.9,17

 

 

 

 

See above.
  • Sulfate-free PEG 4L (US) or low-volume PEG may be better tolerated than PEG 4 L.1,9,10,13,18
  • PEG 2 L plus magnesium citrate or PEG without electrolytes appear more tolerable than PEG 4 L.9,11,15,16
  • To improve taste:18,19
    • drink cold (keep refrigerated)
    • drink through a straw
    • rub a sliced lemon or lime on the tongue
    • add sugar-free flavoring (e.g., Crystal Light)5,6,20
  • Sulfate-free preps (US) taste a little less salty and may be preferred by some patients.21
  • If patient has nausea, bloating, or abdominal cramping, patient can slow or pause drinking solution and drink additional water until symptoms lessen.22

 

 

 

 

 

See above.

Low-volumef

US: MoviPrep ($125)

Canada:

MoviPrep ($25)

Evening before (~10 to 12 hours prior to dose 2):8,30 Mix the 2 pouches with 1 L lukewarm water. Drink over ~1 hour, then drink at least 0.5 L of clear fluid before bed.

Day of:8,30 Repeat above steps, finishing
at least 2 hours (1 hour in Canada) before colonoscopy.

Low-volumef

US only: Plenvu ($140)

Evening before (~12 hours prior to dose 2):31 Mix one dose with 500 mL of lukewarm water. Drink over ~30 minutes. Then drink at least 0.5 L of clear fluid over
30 minutes. Drink additional fluids before bed.

Day of:31 Repeat above steps, finishing at least 2 hours prior to colonoscopy.

Low-volume (does not contain ascorbate)

US only: Suflave ($125)

Evening before:22 reconstitute 1 dose with water and add flavoring packet. Drink over ~1 hour. Drink an additional 480 mL of water.

Day of(~5 to 8 hours prior and at least
4 hours after dose 1):22 Repeat above steps, finishing at least 2 hours prior.

Low-volume* plus bisacodyl

US: PEG-Prep and Bisacodyl ($79)

Canada: 

Bi-PegLyte ($25)

(*Can also use ½ of the PEG 4L product)

Day before:19,22 Dilute each sachet in
1 L of lukewarm water, then refrigerate. Take 10 mg (15 mg in Canada) bisacodyl at the time instructed by prescriber. After a bowel movement, or 6 hours after the bisacodyl dose, drink 1 L (250 mL every
10 minutes) of solution.

Day of:19,22 ~4 hours before colonoscopy, drink 1 L (250 mL every ten minutes) of prepared solution.

Polyethylene glycol (PEG) 3350 WITHOUT electrolytes (off-label):11 osmotic, nonabsorbable, cleanses intestinal lumen via cathartic effect.5,11,19

  • may be combined with magnesium citrate or bisacodyl.17 Becomes hyposmotic when combined with an electrolyte sports drink.5
  • second-line option.22

Multiple formulations

US: Clearlax, Gavilax, Miralax
(~$6/238 g bottle)

Canada: Clearlax, Lax-A-Day, RestoraLAX

(~$12/238 g bottle)

Mix 1 bottle (238 g) with 2 L of light-coloured or clear carbohydrate-electrolyte drink (sports drink), then:3,11,16,22

Evening before: Drink 1 L (250 mL every 10 minutes).

Day of: ~ 5 hours before colonoscopy, drink remaining 1 L (250 mL every
10 minutes).
  • Split-dose PEG 4 L may be more effective than split-dose PEG 3350 without electrolytes with or without bisacodyl.11,15,16
  • May be better tolerated than PEG with electolytes.11,13,15,16
  • Fluid and electrolyte loss can occur. Use with caution in patients with heart failure, kidney impairment, or advanced liver disease.1

Sodium sulfate, magnesium sulfate, potassium sulfate or potassium chloride: small-volume, hyperosmotic solution or tablets that draws water into the intestinal lumen to exert its purgative effect.23,24

US only: 

Suprep ($115/2 x 177 mL bottles)

(contains potassium sulfate)

Evening before:24  Drink one 177 mL bottle diluted to 500 mL with water. Then drink an additional 1 L of water over ~1 hour.

Day of:24  Repeat the above steps. Start
~10 to 12 hours after the first dose and finish at least 2 hours before colonoscopy.
  • As effective or slightly more effective than PEG 2 L (1/2 4L) plus bisacodyl, PEG 4 L, and sodium picosulfate, citric acid, and magnesium oxide products.4,13,25
  • Appears more tolerable than
    PEG 4 L.13,25
  • Use with caution in patients with heart failure, kidney impairment, or advanced liver disease, as can cause fluid shifts and electrolyte abnormalities.1,7,23
  • Avoid in patients taking meds that may increase the risk of kidney injury (e.g., ACEIs, ARBs, diuretics, NSAIDs).23,24
  • Similar in administration to sodium phosphate; however, phosphate free so no risk of acute phosphate nephropathy.22,24

US only: 

Sutab ($165/24 tablets)

(contains potassium chloride)

Evening before:23 Take 12 tablets with
0.5 L of water over 15 to 20 minutes. Then ~1 hour after taking the tablets, drink an additional 500 mL of water over
30 minutes, wait 30 minutes then drink another 500 mL of water over 30 minutes.

Day of:23  Repeat the above steps. Starting ~5 to 8 hours before colonoscopy and at least 4 hours after starting the first dose.

Sodium picosulfate, citric acid, and magnesium oxide: combines stimulant effect (sodium picosulfate) to increase motility with hyperosmotic effect (magnesium oxide and citric acid) to induce diarrhea.5

  • consider over PEG for patients WITHOUT heart failure, kidney impairment or advanced liver disease, due to better tolerability.7,12,14

US:
Clenpiq ($175/2 bottles)

Evening before: drink one bottle, followed by 5 x 250 mL of clear liquids.

Day of(~5 hours prior): drink one bottle followed by 3 x 250 mL of clear fluids (finish within 2 hours of colonoscopy).
  • Appears similar to or slightly more effective than
    PEG 4 L.4,9,12,14
  • Appears to be as effective as PEG 2 L plus bisacodyl and oral sodium phosphate products (US).12,27
  • Appears to be more tolerable than PEG 4 L and PEG 2 L plus bisacodyl.7,9,12,13,27
  • Use with caution in patients with heart failure, kidney impairment, or advance liver disease.1,4,7
  • Adequate hydration may improve safety and tolerability by minimizing electrolyte and fluid shifts.9
  • Consider avoiding with meds that increase the risk of kidney injury (e.g., ACEIs, ARBs, diuretics, NSAIDs).

Canada:

Pico-Salax

($31/2 sachets)

Purg-Odan

($25/2 sachets)

Evening before (~5PM):26 drink 1 sachet in 150 mL cold water. Then (over 4 hours) drink 1.5 to 2 L of a variety of clear liquids (water, Gatorade, fruit juice, clear broth, black coffee or tea) and/or a balanced electrolyte solution (NOT just water).

Day of (~6 hours prior):26  Repeat above steps. Finish all fluids at least 2 hours prior to colonoscopy.

Magnesium citrate: (off-label) hyperosmotic. Draws fluid into the intestine, increasing motility, causing fluid and electrolytes to induce diarrhea.5

  • Not recommended for routine use; generally last choice, due to limited efficacy data and adverse effects (e.g., hypermagnesemia).5

US: Citroma (~$2/300 mL)

Canada: Citrodan, Citro-Mag ($5/300 mL bottle)

Evening before:17 1 bottle (300 mL)

Day of:17 1 bottle (300 mL) 3 to 5 hours before colonoscopy.
  • Rarely used alone as a colonoscopy preparation due to poor efficacy.5,9
  • Risk of hypermagnesemia, especially in the elderly and patients with impaired kidney function.9,17

Although not recommended for bowel prep due to adverse effects, sodium phosphate (US only) oral products have been used. They are hyperosmotic and work by drawing water into the bowel and increasing peristalsis.4,5

  • Higher risk of electrolyte/fluid imbalances (≤20% of patients have low potassium) compared to PEG.9
  • Rare, serious reports (boxed warning) of acute phosphate nephropathy when used orally for bowel prep.28

Abbreviations: ACEIs = angiotensin converting enzyme inhibitors; ARB = angiotensin receptor blockers; ELS = electrolyte lavage solution; GI = gastrointestinal; NSAIDs = nonsteroidal anti-inflammatory drugs; OTC = over-the-counter; PEG = polyethylene glycol.

  1. Pricing based on wholesale acquisition cost (WAC). Cost of generics (where available) may be lower than brand products. Medication pricing by Elsevier, accessed November 2024.
  2. Bowel preps have a significant number of precautions and considerations. Refer to product labeling for complete details.
  3. Split dosing (as provided) is preferred to improve efficacy and tolerability of bowel preps.4,5 If split dosing is not possible, refer to product labeling for single-day dosing (i.e., entire dose is taken in one day; doses separated by several hours).
  4. It is common practice to ONLY drink clear fluids the day before a colonoscopy. Some recommend a low residue diet (avoiding high-fiber or difficult to digest foods [e.g., whole grains, nuts, raw fruits, raw vegetables]) for a few days before a colonoscopy.5,7,17,26 These dietary changes may improve the effectiveness of bowel preps.4
  5. Case reports of ischemic colitis with bowel prep regimes.29
  6. Low-volume PEG products are often referred to in studies as “low-volume PEG with ascorbate” to better differentiate them from other PEG products.
  7. The timing of dosing may need to be adjusted based on the scheduled time of the colonoscopy (e.g., if the colonoscopy is scheduled in the afternoon). Note that many prescribers and clinics may have their own instruction protocols that differ from the above dosing and timing guidance.

Levels of Evidence

In accordance with our goal of providing Evidence-Based information, we are citing the LEVEL OF EVIDENCE for the clinical recommendations we publish.

Level

Definition

Study Quality

A

Good-quality patient-oriented evidence.*
  1. High-quality randomized controlled trial (RCT)
  2. Systematic review (SR)/Meta-analysis of RCTs with consistent findings
  3. All-or-none study

B

Inconsistent or limited-quality patient-oriented evidence.*
  1. Lower-quality RCT
  2. SR/Meta-analysis with low-quality clinical trials or of studies with inconsistent findings
  3. Cohort study
  4. Case control study

C

Consensus; usual practice; expert opinion; disease-oriented evidence (e.g., physiologic or surrogate endpoints); case series for studies of diagnosis, treatment, prevention, or screening.

*Outcomes that matter to patients (e.g., morbidity, mortality, symptom improvement, quality of life).

[Adapted from Ebell MH, Siwek J, Weiss BD, et al. Strength of Recommendation Taxonomy (SORT): a patient-centered approach to grading evidence in the medical literature. Am Fam Physician 2004;69:548-56. https://www.aafp.org/pubs/afp/issues/2004/0201/p548.html.]

References

  1. Parekh PJ, Oldfield EC 4th, Johnson DA. Bowel preparation for colonoscopy: what is best and necessary for quality? Curr Opin Gastroenterol. 2019 Jan;35(1):51-57.
  2. Sharara AI, Bou Daher H. Bowel Cleansing Strategies After Suboptimal BowelPreparation. Clin Gastroenterol Hepatol. 2019 Jun;17(7):1239-1241.
  3. Gardezi SA, Tibbatts C. Improving bowel preparation for colonoscopy in a cost effective manner. BMJ Qual Improv Rep. 2017 May 17;6(1):u204560.w5376.
  4. Hassan C, East J, Radeelli F, et al. Bowel preparation for colonoscopy: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2019. Endoscopy. 2019 Aug;51(8):775-794.
  5. ASGE Standards of Practice Committee, Saltzman JR, Cash BD, et al.Bowel preparation before colonoscopy. Gastrointest Endosc. 2015 Apr;81(4):781-94.
  6. Stop colon cancer now. Five red and purple foods to avoid before your colonoscopy. http://stopcoloncancernow.com/spread-awareness/news/five-red-and-purple-foods-to-avoid-before-your-colonoscopy. (Accessed November 6, 2024).
  7. Sweetser S, Baron TH. Optimizing bowel cleansing for colonoscopy. Mayo Clin Proc. 2015 Apr;90(4):520-6.
  8. Product monograph for MoviPrep. Aralez Pharmaceuticals. Mississauga, ON L5N 6J5. August 2021.
  9. Barkun A, Chiba N, Enns R, et al. Commonly used preparations for colonoscopy: efficacy, tolerability, and safety--a Canadian Association of Gastroenterology position paper. Can J Gastroenterol. 2006 Nov;20(11):699-710.
  10. Wexner SD, Beck DE, Baron TH, et al. A consensus document on bowel preparation before colonoscopy: prepared by a task force from the American Society of Colon and Rectal Surgeons (ASCRS), the American Society for Gastrointestinal Endoscopy (ASGE), and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES). Dis Colon Rectum 2006;49:792-809.
  11. Samarasena JB, Muthusamy VR, Jamal MM. Split-dosed MiraLAX/Gatorade is an effective, safe, and tolerable option for bowel preparation in low-risk patients: a randomized controlled study. Am J Gastroenterol. 2012 Jul;107(7):1036-42.
  12. van Lieshout I, Munsterman ID, Eskes AM, et al. Systematic review and meta-analysis: Sodium picosulphate with magnesium citrate as bowel preparation for colonoscopy. United European Gastroenterol J. 2017 Nov;5(7):917-943.
  13. Gu P, Lew D, Oh SJ, et al. Comparing the Real-World Effectiveness of Competing Colonoscopy Preparations: Results of a Prospective Trial. Am J Gastroenterol. 2019 Feb;114(2):305-314.
  14. Kao D, Lalor E, Sandha G, et al. A randomized controlled trial of four precolonoscopy bowel cleansing regimens. Can J Gastroenterol. 2011 Dec;25(12):657-62.
  15. Enestvedt BK, Brian Fennerty M, Zaman A, et al. MiraLAX vs. Golytely: is there a significant difference in the adenoma detection rate? Aliment Pharmacol Ther. 2011 Oct;34(7):775-82.
  16. Hjelkrem M, Stengel J, Liu M, et al. MiraLAX is not as effective as GoLytely in bowel cleansing before screening colonoscopies. Clin Gastroenterol Hepatol. 2011 Apr;9(4):326-332.e1.
  17. Johnson DA, Barkun AN, Cohen LB, et al. Optimizing adequacy of bowel cleansing for colonoscopy: recommendations from the U.S. multi-society task force on colorectal cancer. Gastrointest Endosc. 2014 Oct;80(4):543-562.
  18. Bowel prep guide. How to increase the tolerability of bowel prep agents. http://bowelprepguide.com/how-to-increase-the-tolerability-of-bowel-prep-agents/. (Accessed November 6, 2024).
  19. Product monograph for Bi-PegLyte. Pendopharm. Montreal, QC H4P 2T4. March 2021.
  20. Stop colon cancer now. Colonoscopy prep tips. http://www.stopcoloncancernow.com/colonoscopy/colonoscopy-prep/colonoscopy-prep-tips. (Accessed November 27, 2024).
  21. Yale Medicine. Which colonoscopy prep is right for you? April 18, 2024. Which Colonoscopy Prep Is Right for You? > News > Yale Medicine. (Accessed November 24, 2024).
  22. Clinical Pharmacology powered by ClinicalKey. Tampa (FL): Elsevier; 2024. http://www.clinicalkey.com. (Accessed November 27, 2024).
  23. Product information for Sutab. Braintree Laboratories. Holbrook, MA 02343. October 2023.
  24. Product information for Suprep. Braintree Laboratories. Holbrook, MA 02343. August 2020.
  25. Harrison NM, Hjelkrem MC. Bowel cleansing before colonoscopy: Balancing efficacy, safety, cost and patient tolerance. World J Gastrointest Endosc. 2016 Jan 10;8(1):4-12.
  26. Product monograph for Pico-Salax. Ferring Pharmaceuticals. North York, ON M2J 5C1. November 2018.
  27. Katz PO, Rex DK, Epstein M, et al. A dual-action, low-volume bowel cleanser administered the day before colonoscopy: results from the SEE CLEAR II study. Am J Gastroenterol. 2013 Mar;108(3):401-9.
  28. FDA. FDA drug safety communication: FDA warns of possible harm from exceeding recommended dose of over-the-counter sodium phosphate products to treat constipation. January 15, 2016. https://www.fda.gov/Drugs/DrugSafety/ucm380757.htm. (Accessed November 27, 2024).
  29. Kawamura T, Sakiyama N, Tanaka K, et al. Ischemic Colitis Caused by Bowel Preparation for Colonoscopy. Gastroenterology Res. 2021 Oct;14(5):296-303.
  30. Product information for MoviPrep. Salix Pharmaceuticals. Bridgewater, NJ 08807. June 2023.
  31. Product information for Plenvu. Salix Pharmaceuticals. Bridgewater, NJ 08807. September 2023.

Cite this document as follows: Clinical Resource, Comparison of Bowel Preps. Pharmacist’s Letter/Pharmacy Technician’s Letter/Prescriber Insights. December 2024. [401268]


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