Can I use miralax (polyethylene glycol) and gatorade to prep for my colonoscopy tomorrow, or do I have to use golytely?

Discuss. Your prep with the endoscopist scheduled to perform the exam. Discuss your preferences with the doctor and do it quickly as you don't have enough time to dally if you expect to get the scope successfully completed.
Maybe. Miralax (polyethylene glycol) has ingredients simialr to the peg preps like go-lytely. Howver, the commercial preps are balanced in the make-up of the chemicals and have been tested for safety and efficacy. The miralax/gatorade prep may not produce adequate cleansing so your procedure will be unsuccessful and will have to be redone. Also the electrolyte imbalance can be harmful, .