First of all welcome to the site deb
Sorry to hear about your Dad. You did'nt give us much info about him. Is he on hemo dialysis and if he is are they still giving it him in hospital? Why are they giving him all this fluid if he is on dialysis. I would start asking questions. Having a colonoscopy is quite common and straight forward, yes, you have to take the stuff that empties your bowels but you take that the day before.Why did he need 3 days on a fluid diet? is he out of hospital? Let us know.