- Polyethylene glycol causes the stool to retain water, which softens the stool and increases the number of bowel movements. This type of medicine is called an osmotic laxative, more gentle than a stimulant laxative.
- This drug also is used along with a stimulant laxative and an electrolyte replacement to empty the lower gastrointestinal tract before a colonoscopy. People with kidney disorders or severe liver or heart disease should not use this preparation.
- Polyethylene glycol can cause diarrhea, especially when taken in larger amounts than normally recommended. Other side effects may include abdominal pain and bloating.
- The preparation for colon cleansing before a colonoscopy can cause cramps, nausea and vomiting. Rectal irritation is to be expected.
- As with any laxative, using polyethylene glycol regularly for longer than two weeks can lead to chronic constipation.