Glycerol 2g Suppositories 6'sGlycerol 2g suppositories contains Glycerol 1400 mg which is for occasional use as a stimulant laxative for the treatment of constipation and for emptying the bowels. Glycerin belongs to a class of drugs known as hyperosmotic laxatives. It works by drawing water into the intestines. This effect usually results in a bowel movement within 15 to 60 minutes. For adults, the normal frequency of bowel movements varies from once daily to 1 to 2 times weekly.