Is it good to take diuretics before surgery?

Surgery, especially one as extensive as an extended Tummy tuck, causes significant stress on the body in general and the kidneys to maintain homeostasis of all the systems. Anything you do to change the normal body systems such as taking diuretics or dieting, etc. makes the body's job harder and, therefore, jeopardizes the safety of the procedure. Therefore, do not take diuretics before surgery unless your anesthesiologist has requested you do so and prescribed them.