According to the American College of Gastroenterology monograph, osmotic laxatives contain poorly absorbed ions or molecules which help in water retention in the intestinal lumen. It was reported that frequently used osmotic agents in the treatment of chronic idiopathic constipation (CIC) include polyethylene glycol (PEG), lactulose, magnesium hydroxide, magnesium citrate, magnesium sulfate, and sodium phosphate. PEG has been found to be effective in improving symptoms of CIC.

Hence, PEG was strongly recommended for the treatment of CIC owing to its efficacy in increasing stool frequency and improving stool consistency; a high quality of evidence was detected for the same. Furthermore, it was stated that varying levels of evidence support that PEG is effective in chronic constipation.