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HalfLytely and Bisacodyl Side Effects

Generic name: bisacodyl / polyethylene glycol 3350 / potassium chloride / sodium bicarbonate / sodium chloride

Medically reviewed by Last updated on Apr 1, 2024.

Note: This document contains side effect information about bisacodyl / polyethylene glycol 3350 / potassium chloride / sodium bicarbonate / sodium chloride. Some dosage forms listed on this page may not apply to the brand name HalfLytely and Bisacodyl.

Applies to bisacodyl / polyethylene glycol 3350 / potassium chloride / sodium bicarbonate / sodium chloride: oral kit.


Use only as directed. Tell your doctor if you use other medicines or have other medical conditions or allergies.

Get emergency medical help if you have signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Stop using bisacodyl and PEG-3350 and call your doctor at once if you have:

Tell your doctor right away if you have trouble drinking clear liquid.

Common side effects may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects.

For Healthcare Professionals

Applies to bisacodyl/polyethylene glycol 3350/potassium chloride/sodium bicarbonate/sodium chloride: oral kit.


Mallory-Weiss tears are quite rare with administration of PEG-ELS. In one study it occurred in only 0.06% of over 3,000 patients.

Complete rectal prolapse was reported in a 71-year-old who had been given 4 L of PEG-ELS. The patient was observed for 2 days and had no recurrence of the prolapse.

During administration of PEG-ELS (4 liters) two deaths occurred in patients with end-stage renal failure following the development of vomiting, diarrhea and dysnatremia.[Ref]

Gastrointestinal side effects have been reported the most frequently. These have included nausea (17.1%), cramping (9.1%), abdominal fullness (22.3%), vomiting (5.9%) and overall discomfort (19.1%).

A small percentage of patients who received PEG-ELS have reportedly experienced Mallory-Weiss tears of the esophagus and esophageal perforation. In addition, at least one case of rectal prolapse has been reported.[Ref]


Dermatologic side effects reported with PEG-ELS have rarely included urticaria and dermatitis.[Ref]


Cardiac arrhythmias, especially increased ventricular ectopy, have been associated with PEG-ELS use.

The manufacturer notes an isolated case of asystole following ingestion of PEG-ELS in a geriatric patient (equal to or greater than 60 years of age).[Ref]

Cardiovascular side effects of PEG-ELS have included arrhythmias and asystole.[Ref]


A 70-year-old male developed shortness of breath, wheezing, skin flushing, and lowered blood pressure after drinking a second glass of PEG-ELS.[Ref]

Hypersensitivity side effects with PEG-ELS have rarely included anaphylaxis.[Ref]


Other side effects with PEG-ELS have included rhinorrhea.[Ref]


The manufacturer notes isolated reports of 'butterfly-like' infiltrate on chest X-ray following vomiting and aspiration of PEG-ELS and sudden dyspnea with pulmonary edema in geriatric patients (equal to or greater than 60-years-old).[Ref]

Respiratory side effects with PEG-ELS have included sudden dyspnea with pulmonary edema, and 'butterfly-like' infiltrate on chest X-ray.[Ref]

Nervous system

Tonic-clonic seizures have been reported in patients with and without previous history of seizures following administration of PEG-ELS (4 liters).[Ref]

Nervous system side effects have included tonic-clonic seizures.[Ref]

More about HalfLytely and Bisacodyl (bisacodyl / polyethylene glycol 3350 / potassium chloride / sodium bicarbonate / sodium chloride)

Patient resources

Related treatment guides


1. Andorsky RI, Goldner F. Colonic lavage solution (polyethylene glycol electrolyte lavage solution) as a treatment for chronic constipation: a double-blind, placebo-controlled study. Am J Gastroenterol. 1990;85:261-5.

2. DiPalma JA, Brady CE 3d. Colon cleansing for diagnostic and surgical procedures: polyethylene glycol-electrolyte lavage solution. Am J Gastroenterol. 1989;84:1008-16.

3. Santoro MJ, Chen YK, Collen MJ. Polyethylene glycol electrolyte lavage solution-induced Mallory-Weiss tears. Am J Gastroenterol. 1993;88:1292-3.

4. Bowden TA Jr, DiPiro JT, Michael KA. Polyethylene glycol electrolyte lavage solution (PEG-ELS). A rapid, safe mechanical bowel preparation for colorectal surgery. Am Surg. 1987;53:34-6.

5. Brinberg DE, Stein J. Mallory-Weiss tear with colonic lavage. Ann Intern Med. 1986;104:894-5.

6. Raymond PL. Mallory-Weiss tear associated with polyethylene glycol electrolyte lavage solution. Gastrointest Endosc. 1991;37:410-1.

7. McBride MA, Vanagunas A. Esophageal perforation associated with polyethylene glycol electrolyte lavage solution. Gastrointest Endosc. 1993;39:856-7.

8. Korkis AM, Miskovitz PF, Yurt RW, Klein H. Rectal prolapse after oral cathartics. J Clin Gastroenterol. 1992;14:339-41.

9. Product Information. HalfLytely and Bisacodyl (bisacodyl-PEG 3350 with electrolytes). Braintree Laboratories. 2022.

10. Marsh WH, Bronner MH, Yantis PL, Kilgore JW, Rickoff MI. Ventricular ectopy associated with peroral colonic lavage. Gastrointest Endosc. 1986;32:259-63.

11. Schuman E, Balsam PE. Probable anaphylactic reaction to polyethylene glycol electrolyte lavage solution. Gastrointest Endosc. 1991;37:411.

Further information

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

Some side effects may not be reported. You may report them to the FDA.