I have read the attachment.
There is no easy answer to this situation, as I am sure that you realize.
A colonoscopy is difficult to do in someone that has difficulty drinking large amounts of fluids. There are “low volume” preps, but that is slightly misleading, as it only refers to the volume of the prep,itself. For optimal effectiveness, it typically requires drinking additional water, usually about 2 liters in volume. If she is sensitive to the prep, but can drink water, then this would be a good option, but it sounds from your description that she would have difficulty drinking large volumes of water.Another option is to try to use split dosing of the prep, so that half of the prep is taken on two consecutive days.
It also would be appropriate to discuss the worsening elevation of the alkaline phosphatase with the Gastroenterologist. It may help to perform an MRCP to look at the bile ducts.
Another option to consider would be traveling to a major national medical center, such as the Mayo Clinic. The Mayo Clinic in Minnesota is highly ranked across all the specialties involved in this situation. There also is a Mayo Clinic in Jacksonville, which is not as highly ranked, but can access the resources of the Mayo Clinic in Minnesota. Shands in Gainesville is also well ranked. It is when there is a difficult diagnostic dilemma that such a consultation is most valuable, and if this was my mother, this is the step that I would strongly consider.