What is Gavilyte-G: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

GaviLyte-G is a brand-name bowel preparation laxative. Its active ingredients are PEG 3350, a gentle osmotic laxative, and electrolytes. GaviLyte-G comes as a powder and has to be mixed with water. All doses from the mixture are taken the day before the colon procedure.

Gavilyte-G overview

BRAND NAMES:

  • GaviLyte-G

Generic Names:

  • Polyethylene glycol 3350 plus electrolytes

Uses:

  • Helps empty your bowels before a medical test.

Therapeutic Classes:

  • Osmotic laxative

Forms:

  • Powder

How it’s taken:

  • By mouth

What is Gavilyte-G used for?

Gavilyte-G cleans out the intestines before certain bowel exam procedures such as a colonoscopy or barium enema X-ray.

What form(s) does Gavilyte-G come in

  • Powder

    • 230 g polyethylene glycol 3350

What are common Gavilyte-G doses?

  • For bowel preparation prior to a colonoscopy or barium enema: One pack (230 g PEG 3350) added to four liters of water; drink eight ounces every 10 minutes

Common Gavilyte-G prescriptions

  • GaviLyte-G
    236gm of peg 3350/4000ml bottle

How to take Gavilyte-G

  • The clinic or prescriber will provide you with an instruction sheet. Please read and follow this instruction sheet. 

  • Please follow the instructions printed on the side of the bottle when mixing and taking this medication.

  • This medicine comes as a powder that you mix with water before you drink it. Do not swallow the powder directly. 

  • If you want the lemon flavor pack added to the mixture, ask the pharmacist to do this when you pick up the medicine at the pharmacy.

  • This medicine is taken throughout the day preceding a colonoscopy, barium enema, or other colon procedure. 

  • Start taking doses in the morning or at the time indicated in the clinic’s instruction sheet.

    • Do not eat solid food at least three to four hours before you start taking doses.

    • Do not eat solid food after you start taking doses.

    • Follow the liquids intake instructions given by the clinic or prescriber.

  • To prepare the medicine, add lukewarm water to the bottle until it reaches the fill line (four liters). 

  • Replace the cap and shake the bottle vigorously.

  • Rapidly drink one eight-ounce glass or cup of the mixture every 10 minutes until the mixture runs out or you have drunk the amount prescribed by the doctor.

    • There are 17 eight-ounce doses in a four-liter container of liquid, so it should take about three hours to drink the entire container.

  • Store the mixture in the refrigerator to make it more palatable.

What to do if you miss a dose of Gavilyte-G

  • If a dose is missed, take it when remembered.

  • Return to the 10-minute dosing schedule.

  • Do not take a double dose to make up for a missed dose.

  • The clinic or prescriber will provide written instructions about what to do if too many doses are missed, doses are started late in the day, or no doses are taken. The procedure may need to be rescheduled.

  • If you’re unsure, call the clinic or prescribing healthcare provider.

Gavilyte-G contraindications

  • This medicine is not right for everyone. 

  • Do not use it if you have:

    • Gastrointestinal blockage

    • Stomach emptying problems (gastric retention)

    • An opening in the intestine or stomach (bowel perforation)

    • Slow movement of food through the colon (ileus)

    • Severe colon swelling (toxic colitis)

    • Known allergies to PEG 3350 or any of the other ingredients in the mixture

Gavilyte-G warnings

  • Before using this medicine, tell the prescriber if you are pregnant, breastfeeding, or have any medical problems, particularly:

    • Heart problems

    • Heart rhythm abnormalities

    • Digestive system problems

    • Problems swallowing

    • Gastric reflux

    • Ulcerative colitis

    • A history of seizures

    • Low sodium levels

    • Kidney problems

  • Gavilyte G can cause serious problems including:

    • Dehydration

    • Electrolyte imbalance

    • Low blood pressure

    • Heart rhythm irregularities

    • Kidney problems

    • Seizures

    • Bowel ulcers

    • Bowel inflammation or damage due to blood flow problems (ischemic colitis)

Gavilyte-G interactions

  • Do not take stimulant laxatives on the day you’re taking GaviLyte-G.

  • GaviLyte-G will interfere with the absorption and effectiveness of most oral medications. You should stop taking oral medications one hour before starting GaviLyte-G doses. 

    • Talk to the prescriber if you’re taking essential oral medications such as blood thinners.

  • Tell the prescriber about all medications that you are taking, particularly:

    • Any medication taken by mouth

    • Other laxatives

    • NSAIDS such as aspirin or ibuprofen

    • Blood pressure medications

    • Heart medications

    • Seizure medications

    • Drugs that make you urinate (diuretics)

Gavilyte-G side effects

Serious side effects

Call a healthcare provider if you notice any signs or symptoms of a possible serious side effect, including:

  • Nausea, vomiting, difficulty keeping a drink or dose down

  • Decrease in how much or how often you urinate

  • Dizziness, lightheadedness, feeling faint

  • Fast, pounding, or uneven heartbeat

  • Chest pain, trouble breathing

  • Confusion, weakness, muscle cramps or twitching

  • Severe stomach pain, rectal bleeding

  • Allergic reactions: rash, hives, itching, trouble breathing, trouble swallowing, swelling of the face, lips, throat, or mouth

Less serious side effects

  • Mild nausea

  • Bloating

  • Feeling of fullness

  • Vomiting

  • Stomach cramps or pain

  • Anal irritation

Sources:

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