Hey Sweety,
I am sorry to be slow in getting to your question but I wanted to double check on something.
GI Physicians were using the Fleet Phosphate including my GI. You only had to drink one small bottle if I remember that correctly. It has been found to cause kidney failure after colonoscopy. ( Acute Phosphate Nephropathy)
My GI like many others have switched back to Golytely . I have heard of physicians using Miralax but I think you have to drink large quanties of fluids with this prep too.
I do not have any suggestions other then talking to your physician to see if there is something else you could take.
Wish I had a good answer for you. Take care
Kitt