Do I need to drink more than 64oz water when taking miralax (polyethylene glycol)?

Constipated or prep? The recommendation for taking MiraLAX (polyethylene glycol) is to mix it (17gm dose) with 4-8 oz of water, fruit juice to dissolve for the use of constipation. Now if you are talking about the MiraLAX (polyethylene glycol) bowel prep for colonoscopies, then you should mix the 238gm bottle with 64 oz of gatorade. This is a non-fda approved use however although used quite commonly for preps.