Is Sutab less liquid than Suprep?

No. The Sutab label requires 48 ounces of water with each 12-tablet dose, which is 96 ounces in total. The Suprep label also totals 3 quarts. The difference is that all of the Sutab liquid is plain water.

Is Miralax with Gatorade FDA-approved for colonoscopy prep?

No. The MiraLAX label covers occasional constipation at 17 grams a day for up to 7 days. The 2025 US Multi-Society Task Force recommendations state that the PEG-3350 and sports drink regimen is widely used but not FDA-approved as a bowel preparation.

Can I take Suprep or Sutab if I have kidney disease?

Both labels call for caution in people with impaired kidney function, because these patients may be at risk for kidney injury. The labels advise good hydration and suggest blood tests before and after the exam. Your prescriber decides whether a sulfate prep is suitable for you.

How big is the difference in vomiting between Sutab and Suprep?

The labels report vomiting in 16% to 23% of Sutab patients and 8% of Suprep patients. These numbers come from different trials that measured symptoms in different ways. The FDA labels warn against comparing rates across trials, so treat the gap as a rough signal only.

Can children take Sutab or Suprep?

The Sutab label says safety and effectiveness in children have not been established. Suprep is approved for patients 12 and older, who get a smaller 4.5-ounce bottle. A pediatric specialist chooses the prep for a child.

Suprep vs. Sutab vs. Miralax With Gatorade: Which Colonoscopy Prep Is Easiest to Tolerate?

The short answer: No trial has compared all three preps head to head, so no single one is proven easiest. In the trials on its FDA label, Sutab (24 tablets) caused nausea in about half of patients and vomiting in 16% to 23%. Suprep caused nausea in 36% and vomiting in 8% in its own trial. Miralax with a sports drink is the regimen patients most often say they would repeat, but it is not FDA-approved for bowel prep and it cleaned less well in pooled trials. Your prescriber picks the prep based on your kidneys, heart and medicines.

What are Suprep, Sutab, and Miralax with Gatorade?

All three are osmotic laxatives.

Suprep is a prescription liquid of sodium sulfate, potassium sulfate and magnesium sulfate. The Suprep label on DailyMed approves it for colon cleansing before colonoscopy in adults and in children 12 and older.
Sutab is a prescription tablet of sodium sulfate, magnesium sulfate and potassium chloride. The Sutab label on DailyMed approves it for adults only.
Miralax with a sports drink uses over-the-counter polyethylene glycol 3350 (PEG-3350). The MiraLAX Drug Facts label lists one use: relief of occasional constipation, at 17 grams once a day for no more than 7 days. Bowel prep is an off-label use.

The 2025 US Multi-Society Task Force on Colorectal Cancer recommendations say the PEG-3350 regimen, "though widely used," is not approved by the FDA as a bowel preparation. That paper updates the 2014 version.

How much liquid or how many tablets does each prep take?

The tablet prep is not a low-liquid prep. Adult amounts:

Suprep: two 6-ounce bottles. You dilute each bottle with water to 16 ounces, then drink 32 more ounces of water over the next hour. The label puts the total at 3 quarts of liquid.
Sutab: 24 tablets, taken as two doses of 12. You swallow each dose with 16 ounces of water over 15 to 20 minutes, then drink 32 more ounces. That is also 3 quarts in total.
Miralax with a sports drink: the Task Force table lists 238 grams of PEG-3350 mixed into 2 liters of sports drink, half the night before and half on the day of the exam.

The main difference is taste. With Suprep, 32 of the 96 ounces carry the salty sulfate flavor. With Sutab, all of the liquid is plain water. With Miralax, all of it tastes like the sports drink. For general steps and timing, see the complete colonoscopy prep guide.

Which prep causes the least nausea and vomiting?

The trial numbers come from separate studies with different comparison products. FDA labels warn that side effect rates from one drug's trials cannot be directly compared with another's.

Suprep. In its label trial of 379 adults, patients on split-dose Suprep reported overall discomfort (54%), abdominal distension (40%), abdominal pain (36%), nausea (36%) and vomiting (8%). The PEG comparison prep caused nausea in 33% and vomiting in 4%.

Sutab. Two label trials questioned 941 adults about stomach symptoms. In Study 1, 48% of Sutab patients reported nausea and 23% reported vomiting. The comparison group, on a PEG solution with ascorbic acid, reported 26% and 5%. In Study 2, Sutab patients reported nausea in 52% and vomiting in 16%. The sodium picosulfate comparison group reported 18% and 2%. Most Sutab symptoms were mild or moderate.

Miralax with a sports drink. A meta-analysis of five randomized trials (1,418 adults) compared it with 4-liter PEG solutions. Nausea, cramping and bloating did not differ between groups. Patients were far more willing to repeat the Miralax prep (odds ratio 7.32). In a 600-patient randomized trial, the PEG and Gatorade group had less nausea, vomiting and bloating than the 4-liter NuLYTELY group.

Tablets remove the taste problem, but the label numbers show they do not prevent nausea. If you get sick partway through, the post on vomiting during colonoscopy prep explains what to do.

Which prep cleans the colon best?

A poor prep can hide polyps and can mean a repeat exam.

Suprep: 97% of 180 patients had a good or excellent cleanse, against 96% on the PEG comparison prep.
Sutab: 92% had a good or excellent cleanse in both trials, against 89% and 88% on the comparison preps. The label calls Sutab non-inferior in both.
Miralax with a sports drink: the meta-analysis found fewer satisfactory preps than with 4-liter PEG (odds ratio 0.65). In a separate randomized trial of 389 patients, overall cleansing was similar, but excellent preps were less common with the sports drink mix (30% against 52%).

The Task Force did not pick a winner. It does not recommend any one prep as superior for cleansing in outpatients at low risk of a poor prep. It suggests that a 2-liter regimen may be enough for these patients.

Who should avoid each prep?

Both sulfate labels list the same contraindications: bowel obstruction or ileus, bowel perforation, toxic colitis or toxic megacolon, gastric retention, and allergy to an ingredient.

Suprep and Sutab. Both labels warn that fluid and electrolyte changes can lead to abnormal heart rhythms, seizures and kidney injury. They call for caution in people with impaired kidney function and in people who take medicines that affect the kidneys, such as diuretics, ACE inhibitors, ARBs and NSAIDs. Many people take these for blood pressure, a topic covered at hypertension.md. Both labels name congestive heart failure among the conditions that raise the risk of arrhythmia. The Suprep label adds that the prep can raise uric acid for a time, which can trigger a flare in people with gout. The Task Force table classes oral sodium sulfate as hypertonic, and the Task Force recommends against hyperosmotic regimens for people at risk of volume overload or electrolyte disturbances, and it names kidney insufficiency and congestive heart failure.

Sutab only. Each bottle holds a desiccant. The label says to remove and discard it, and warns of gastrointestinal complications if it is swallowed.

Miralax with a sports drink. The MiraLAX label says not to use it if you have kidney disease, except under a doctor's supervision. The Task Force explains that PEG-3350 alone is iso-osmotic but not isotonic, so it must be mixed with a sports drink. Its table lists hyponatremia (low blood sodium) as a possible side effect. In the 389-patient trial, hyponatremia occurred in 3.9% on the sports drink mix and 2.2% on a PEG electrolyte solution. That difference was not statistically significant.

Does split dosing change how tolerable a prep is?

Yes. Split dosing means one dose the evening before and one on the morning of the exam. The Task Force recommends a split-dose regimen for every prep.

Both prescription labels build it in. Both must be finished at least 2 hours before the procedure. The Suprep label reports a 408-patient study in which an evening-only schedule caused more discomfort, nausea and vomiting than the split schedule. It says the evening-only schedule is not recommended.

Comfort measures are covered in our colonoscopy prep tips.

Why does the choice belong to your prescriber?

The Task Force says the choice of prep should weigh patient preference, other health conditions, safety, cost to the patient, and how easy the prep is to get and take.

Suprep and Sutab need a prescription. Both labels tell prescribers to correct fluid and electrolyte problems before treatment and to consider blood tests for patients at risk. Miralax is sold over the counter, but its use as a bowel prep is off-label, so the amount and timing should come from your endoscopy team.

You can still speak up. Tell the office if a past prep made you vomit, if you cannot swallow large tablets, or if you have kidney disease, heart failure, gout or a seizure history.

The bottom line

Miralax with a sports drink has the best record for taste and willingness to repeat, but it cleaned less well in pooled trials and is not FDA-approved for this use. Suprep matched standard PEG for cleansing, with nausea in about a third of patients. Sutab removes the taste but still needs 3 quarts of water, and about half of trial patients felt nauseated. The right prep is the one your prescriber judges safe for you and that you can finish in two doses.

Last updated: October 2026. This article is for informational purposes only and does not constitute medical advice. Follow the prep instructions from your own endoscopy team, and ask them before you switch products or change a dose.