A system and method for surgery on a hollow organ comprises a source of a biocompatible gellable fluid in a flowable state and an insertion device for introducing the gellable fluid into a hollow organ of a patient, the gellable fluid transitioning from the flowable state to a gel-like state to form a gel mass within the hollow organ to support a wall of the hollow organ in combination with a state control apparatus for transitioning the gel mass from the gel-like state to the flowable state and a removal device for removing from the hollow organ the gellable fluid in the flowable state.