Polyethylene Glycol (PEG)


How it works: PEG is an osmotic laxative which causes water to be released into the bowel. PEG softens the stool without interfering with the active absorption of nutrients or electrolytes.

Which symptoms does it help: Consistency and frequency of bowel movements. Little to no effect on pain or bloating in IBS-C patients.

How long it takes to see a benefit: It may take 2 to 4 days for the PEG to produce a bowel movement. It works best when used between one and two weeks.

FDA approved: Constipation.

Dosage: 17 grams daily. The dose is either measured by the dosing cup (or one heaping tablespoonful of powder) or the use of one sachet.

Special considerations or risks: Animal reproductive studies have not been performed with PEG, and it is not known whether PEG can cause fetal harm when administered to a pregnant woman, or can affect reproductive capacity.

Most common side effects: Abdominal cramping, diarrhea, bloating and flatulence.

Recommendation: ACG suggests against PEG for overall symptom improvement in IBS patients. (Recommendation: weak; Quality of evidence: low)