The easiest colonoscopy preps to tolerate are low-volume formulations, which cut the liquid you need to drink roughly in half compared to traditional options. Where older preps require drinking 4 liters (about a gallon) of solution, newer low-volume preps bring that down to 2 liters or less. In clinical comparisons, 44% of patients rated low-volume preps as “easy” or “very easy,” compared to 34% for high-volume versions. Beyond choosing the right formula, how you take it and what you eat beforehand also make a significant difference.
Why Volume Is the Biggest Factor
The single most common complaint about colonoscopy prep is the sheer amount of liquid involved. Traditional preps use a 4-liter polyethylene glycol solution, and many people struggle to finish it. Nausea, bloating, and the taste of salty or chemical-flavored liquid are the main reasons people quit partway through, which leads to a poorly cleaned colon and sometimes a repeat procedure.
Low-volume alternatives use about 2 liters of solution paired with additional water. They clean the colon just as effectively while being meaningfully easier to get through. In head-to-head comparisons, magnesium citrate, the MiraLAX-Gatorade method, MoviPrep, Clenpiq, and Suprep all scored significantly higher in tolerability than the traditional 4-liter GoLYTELY prep.
The MiraLAX-Gatorade Method
One of the most popular options is mixing a bottle of MiraLAX (a tasteless powder laxative) into Gatorade or a similar sports drink. Many patients prefer it because you control the flavor, and the taste is far more palatable than prescription solutions. A randomized controlled trial found that split-dose MiraLAX achieved bowel cleanliness scores comparable to prescription preps, with no significant electrolyte changes in healthy patients afterward.
This method is technically off-label, meaning MiraLAX isn’t FDA-approved specifically for colonoscopy prep. Most gastroenterologists consider it safe for low-risk patients, but it’s typically not recommended for people with severe kidney disease or heart failure. Your doctor’s office will tell you whether this option is on the table for you, and many practices now list it as their default prep.
Tablet Preps: No Liquid Solution at All
If drinking large volumes of flavored liquid is your main concern, tablet-based preps offer a different approach. SUTAB, the main tablet option, involves swallowing 12 tablets the evening before your procedure with at least 16 ounces of water, then another 12 tablets five to eight hours before the colonoscopy with another 16 ounces of water. You still need to drink clear fluids throughout the process, but you skip the flavored solution entirely.
There’s a trade-off, though. In clinical trials, patients taking SUTAB reported more nausea and vomiting than those using MoviPrep (a low-volume liquid). Fewer than 5% experienced severe symptoms, so most people tolerate it well. But if nausea is a bigger concern for you than taste, a liquid prep might actually be the better choice. For people who gag on flavored solutions, tablets can feel like a game-changer.
Low-Volume Liquid Preps
Several prescription liquid preps fall into the low-volume category, each with a slightly different flavor profile and mechanism:
- Clenpiq: Two small 5.4-ounce doses of a cranberry-flavored liquid, taken hours apart. The tiny volume makes it one of the easiest to finish.
- Suprep: Two 6-ounce doses mixed with water, berry-flavored. Each dose brings the total to about 16 ounces of solution plus additional water.
- MoviPrep: A 2-liter prep with citrus flavoring, taken in two split doses. More volume than Clenpiq or Suprep but still half of what traditional preps require.
All of these clean the colon effectively. The differences come down to taste preferences, cost, and insurance coverage. Ask your gastroenterologist’s office which ones your insurance covers before assuming you can use a specific brand.
Split Dosing Makes Any Prep Easier
Regardless of which prep you choose, splitting the dose into two sessions dramatically improves the experience. Instead of drinking everything the night before, you take half the evening before and half the morning of your procedure (typically 5 to 8 hours before your appointment). This approach does two things: it reduces the amount you’re drinking at any one time, and it cleans the right side of the colon more effectively because the second dose is closer to the procedure.
Split dosing improved right-colon cleanliness scores from 1.75 to 2.6 on a 3-point scale in one trial. Skipping or not completing the split dose was the single strongest predictor of a poorly prepped colon, increasing the odds of a suboptimal result nearly sevenfold. The early wake-up is inconvenient, but it’s the single most impactful change you can make to both tolerability and prep quality.
What You Eat Beforehand Matters Too
Many people dread the clear-liquid-only diet the day before a colonoscopy almost as much as the prep itself. The good news: a low-residue diet (white bread, eggs, chicken, pasta, well-cooked vegetables without skins) works just as well. In a large review, 87% of patients on a low-residue diet had adequate bowel preparation compared to 83% on clear liquids only.
Patients who could eat low-residue foods were also significantly more willing to repeat the prep if needed. About 80% said they’d do it again, versus 69% of those restricted to clear liquids. Being less hungry and less miserable the day before your procedure sets you up to actually finish the prep solution that evening, which is what truly determines whether the colonoscopy goes smoothly.
Who Needs to Be Careful With Certain Preps
Most healthy adults can use any of the preps described above. The main exception involves sodium phosphate-based preps (like OsmoPrep tablets), which can stress the kidneys. The FDA has flagged several risk factors for kidney problems with these formulations: older age, existing kidney disease, dehydration, use of blood pressure medications like ACE inhibitors or ARBs, and inflammatory bowel disease. People with low potassium, low calcium, or kidney insufficiency should avoid sodium phosphate preps entirely.
Polyethylene glycol-based preps (GoLYTELY, MoviPrep, MiraLAX) are the safest option for people with kidney disease, liver disease, heart failure, or electrolyte imbalances. The solution passes through the gut without being absorbed, so it doesn’t put extra strain on the kidneys. If you have any chronic health conditions, your doctor will likely steer you toward a PEG-based option regardless of preference.
Practical Tips for Getting Through It
A few strategies make any prep more tolerable. Chill the solution in the refrigerator, since cold liquids have less noticeable taste. Drink through a straw placed toward the back of your mouth to bypass some of your taste buds. Sucking on a lemon wedge or hard candy between glasses can cut the aftertaste. If you’re using a flavored sports drink mix, choose a light color (yellow or clear) so you can still monitor your output, which should eventually look like pale yellow or clear liquid.
Start your low-residue or clear-liquid diet two days before if you tend toward constipation, rather than waiting until the day before. Staying well-hydrated in the days leading up to prep means you’re starting from a better place and less likely to feel wiped out. Keep your evening clear of obligations. You’ll be in the bathroom frequently starting about an hour after your first dose, and that will continue for several hours.