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Polyethylene Glycol-Electrolyte Solution and Bisacodyl

Medically reviewed by Last updated on Aug 12, 2021.


(pol i ETH i leen GLY kol ee LEK troe lite soe LOO shun & bis a KOE dil)

Index Terms

  • Bisac/NaCl/Nahco3/KCl/Peg 3350
  • Bisacodyl and Polyethylene Glycol-Electrolyte Solution
  • Electrolyte Lavage Solution

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Kit [each kit contains]:

GaviLyte-H and Bisacodyl:

Powder for solution, oral (GaviLyte-H): PEG 3350 210 g, sodium bicarbonate 2.86 g, sodium chloride 5.6 g, potassium chloride 0.74 g (2000 mL) [contains 3 flavor packs: cherry, lemon, orange]

Tablet, delayed release, oral (Bisacodyl): 5 mg (1s)

HalfLytely and Bisacodyl [DSC]:

Powder for solution, oral (HalfLytely): PEG 3350 210 g, sodium bicarbonate 2.86 g, sodium chloride 5.6 g, potassium chloride 0.74 g (2000 mL) [contains 4 flavor packs: cherry, lemon-lime, orange, pineapple]

Tablet, delayed release, oral (Bisacodyl): 5 mg (1s)

PEG-Prep and Bisacodyl:

Powder for solution, oral (PEG-Prep): PEG 3350 210 g, sodium bicarbonate 2.86 g, sodium chloride 5.6 g, potassium chloride 0.74 g (2000 mL) [contains 3 flavor packs: cherry, lemon, orange]

Tablet, delayed release, oral (Bisacodyl): 5 mg (1s)

Brand Names: U.S.

  • GaviLyte-H and Bisacodyl
  • HalfLytely and Bisacodyl [DSC]
  • PEG-Prep and Bisacodyl

Pharmacologic Category

  • Laxative, Bowel Evacuant
  • Laxative, Stimulant


Bisacodyl acts on the colonic mucosa to increase peristalsis throughout the large intestine. Polyethylene glycol-electrolyte solution induces catharsis through strong electrolyte and osmotic effects.

Use: Labeled Indications

Bowel cleansing prior to colonoscopy


Gastrointestinal obstruction; bowel perforation; toxic colitis; toxic megacolon; gastric retention; ileus

Bi-Peglyte [Canadian product]: Hypersensitivity to bisacodyl, polyethylene glycol or any component of the formulation; ileus; gastric retention; GI obstruction; bowel perforation; toxic colitis; toxic megacolon; acute surgical abdomen; appendicitis; rectal bleeding; gastroenteritis; diverticulitis

Dosing: Adult

Bowel cleansing: Oral:

Bisacodyl: 5 mg as a single dose. After bowel movement or 6 hours (whichever occurs first), initiate polyethylene glycol-electrolyte solution

Polyethylene glycol-electrolyte solution: 8 ounces every 10 minutes until 2 L are consumed

Dosing: Geriatric

Refer to adult dosing.


Fill the container with water to the fill mark; may add flavor packet provided in kit to the solution; no other ingredients should be added to the solution. Shake well.


Administer bisacodyl tablet with water; do not chew or crush tablet. Do not take antacids within 1 hour of taking bisacodyl. Rapidly drinking the polyethylene glycol-electrolyte solution is preferred to drinking small amount continuously. If severe bloating, distention, or abdominal pain occurs, administration should be slowed or temporarily discontinued until symptoms resolve. Oral medications should not be administered within 1 hour of start of therapy.

Dietary Considerations

Drink only clear liquids the day of and during the bowel preparation; after consuming the solution, avoid drinking large quantities of clear liquids until colonoscopy.


Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F). When polyethylene glycol-electrolyte solution is reconstituted, may refrigerate. Use within 48 hours.

Drug Interactions

Antacids: May diminish the therapeutic effect of Bisacodyl. Antacids may cause the delayed-release bisacodyl tablets to release drug prior to reaching the large intestine. Gastric irritation and/or cramps may occur. Management: Antacids should not be used within 1 hour before bisacodyl administration. Consider therapy modification

Bisacodyl: May enhance the adverse/toxic effect of Polyethylene Glycol-Electrolyte Solution. Monitor therapy

Dichlorphenamide: Laxatives may enhance the hypokalemic effect of Dichlorphenamide. Monitor therapy

Polyethylene Glycol-Electrolyte Solution: Bisacodyl may enhance the adverse/toxic effect of Polyethylene Glycol-Electrolyte Solution. Monitor therapy

Senna: May enhance the adverse/toxic effect of Polyethylene Glycol-Electrolyte Solution. Monitor therapy

Sodium Picosulfate: May enhance the adverse/toxic effect of Polyethylene Glycol-Electrolyte Solution. Monitor therapy

Adverse Reactions

The following adverse drug reactions and incidences are derived from product labeling unless otherwise specified.


Central nervous system: Malaise (57%)

Gastrointestinal: Gastrointestinal fullness (40%), abdominal cramps (38%), nausea (34%)

1% to 10%: Gastrointestinal: Vomiting (10%)

<1%, postmarketing and/or case reports: Anaphylaxis, aspiration, asystole, dermatitis, dizziness, dyspnea, esophageal perforation, hypersensitivity reaction, ischemic colitis, Mallory-Weiss syndrome, pulmonary edema, rhinorrhea, seizure (using the 4 L preparation), syncope, urticaria


Concerns related to adverse effects:

• Arrhythmias: Serious arrhythmias have been reported (rarely) with the use of ionic osmotic laxative products. Use with caution in patients who may be at risk of cardiac arrhythmias (eg, patients with a history of prolonged QT, uncontrolled arrhythmias, recent MI, unstable angina, CHF, or cardiomyopathy). Consider pre-dose and post-colonoscopy ECGs in these patients.

• Fluid/electrolyte loss: Fluid and electrolyte disturbances can lead to arrhythmias, seizures, and renal impairment. Advise patients to maintain adequate hydration before, during, and after treatment. If patient becomes dehydrated or experiences significant vomiting after treatment, consider post-colonoscopy lab tests (electrolytes, creatinine, and BUN).

• Ischemic colitis: Cases of ischemic colitis have been reported; development of severe abdominal pain or rectal bleeding should prompt further evaluation.

• Seizures: Generalized tonic-clonic seizures have occurred in patients with no prior history of seizures when using the large volume (4 L) preparation. Seizures resolved with the correction of fluid and electrolyte abnormalities. Use caution in patients taking medications which increase the risk for electrolyte abnormalities (eg, diuretics) and/or patients with pre-existing electrolyte abnormalities. Evaluation of electrolytes pre- and post-colonoscopy is warranted in this population.

Disease-related concerns:

• Impaired gag reflex: Observe unconscious or semiconscious patients with impaired gag reflex or those who are otherwise prone to regurgitation or aspiration during administration.

• Renal impairment: Use with caution in patients with renal impairment and/or in patients taking medications that may adversely affect renal function (eg, diuretics, NSAIDs, ACE inhibitors). Patients with impaired renal function who develop severe vomiting should be closely monitored including measurement of electrolytes.

• Ulcerative colitis: Use with caution in patients with severe ulcerative colitis.

Other warnings/precautions:

• Appropriate use: Evaluate patients with symptoms of bowel obstruction or perforation prior to use. Correct electrolyte abnormalities in patients prior to use. No additional ingredients or flavors (other than the flavor packs provided) should be added to the polyethylene glycol-electrolyte solution.

Monitoring Parameters

Bowel movements; electrolytes, renal function

Pregnancy Risk Factor C Pregnancy Considerations

Animal reproduction studies have not been conducted with this combination. Refer to individual monographs for additional information.

Patient Education

What is this drug used for?

• It is used to clean out the GI (gastrointestinal) tract.

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call your doctor or get medical help if any of these side effects or any other side effects bother you or do not go away:

• Bloating

• Vomiting

• Nausea

WARNING/CAUTION: Even though it may be rare, some people may have very bad and sometimes deadly side effects when taking a drug. Tell your doctor or get medical help right away if you have any of the following signs or symptoms that may be related to a very bad side effect:

• Fluid and electrolyte problems like mood changes, confusion, muscle pain or weakness, abnormal heartbeat, very bad dizziness or passing out, fast heartbeat, more thirst, seizures, feeling very tired or weak, not hungry, unable to pass urine or change in the amount of urine produced, dry mouth, dry eyes, or nausea or vomiting.

• Severe dizziness

• Passing out

• Severe headache

• Severe abdominal pain

• Rectal bleeding

• Rectal pain

• Vomiting blood

• Signs of an allergic reaction, like rash; hives; itching; red, swollen, blistered, or peeling skin with or without fever; wheezing; tightness in the chest or throat; trouble breathing, swallowing, or talking; unusual hoarseness; or swelling of the mouth, face, lips, tongue, or throat.

Note: This is not a comprehensive list of all side effects. Talk to your doctor if you have questions.

Consumer Information Use and Disclaimer: This information should not be used to decide whether or not to take this medicine or any other medicine. Only the healthcare provider has the knowledge and training to decide which medicines are right for a specific patient. This information does not endorse any medicine as safe, effective, or approved for treating any patient or health condition. This is only a limited summary of general information about the medicine's uses from the patient education leaflet and is not intended to be comprehensive. This limited summary does NOT include all information available about the possible uses, directions, warnings, precautions, interactions, adverse effects, or risks that may apply to this medicine. This information is not intended to provide medical advice, diagnosis or treatment and does not replace information you receive from the healthcare provider. For a more detailed summary of information about the risks and benefits of using this medicine, please speak with your healthcare provider and review the entire patient education leaflet.

More about bisacodyl / polyethylene glycol 3350 / potassium chloride / sodium bicarbonate / sodium chloride

Patient resources

Other brands

HalfLytely and Bisacodyl

Related treatment guides

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.