Using MiraLAX for Colonoscopy
Although MiraLAX® (polyethylene glycol 3350) is approved for treating occasional constipation in adults, there are possible "off-label" (unapproved) uses as well. For example, using MiraLAX for preparing for a colonoscopy procedure is one possible off-label use. However, when used for this purpose, MiraLAX is usually mixed with an electrolyte solution to prevent an electrolyte imbalance.
As a type of osmotic laxative, MiraLAX works by drawing water into the colon, making the stool soft, and increasing the number of bowel movements. It should not be used for longer than seven days unless your healthcare provider tells you to do so.