I too am on my full 4th day post op. I am terribly sore, especially around the incision where my port was put. I am suffering the back aches and am tired, but not having the problem with the fluids, am drinking water and instant breakfasts, slimfasts, etc with no problem. Thought I was going to go back to work tomorrow, but I think I will take another day or two, as it is uncomfortable to sit upright in a chair too long. My husband is an RN and says usually the 4th and 5th day after surgery are the worse so I would try and wait it out till tomorrow to see if you don't feel different, if not then definetly make that call