I Am Getting A Colonoscopy Tomorrow Am, According To My

I am getting a colonoscopy tomorrow am, According to my doctors instructions, I took 4 Dulcolax at 3:00 PM and began drinking a total of 64 ounces of powerade mixed with 14 doses of Miralax. I finished all the liquid by 6:30. My excrement is and has been totally liquid for the past two hours and is currently a light yellowish color. The instructions also indicated that I should take Magnesium Citrate at 10:00 PM. (it is now 8:00 PM) The last time I had this procedure (10 years ago) the instructions said that when my excrement ran clear or mostly clear that I could discontinue drinking any mixture. I don't want to over medicate so I'm wondering if the Magnesium Citrate is necessary?