TURP is performed with a nonhemolytic fluid such as 1.5% glycine. Saline cannot be used because electrolytes in the irrigation fluid will dissipate the electric current used to resect the prostate." -- Schwaz 8/e p1530 During transurethral resection of, prostate strips of tissue are cut from the bladder neck down to the level of verumontanum. This cutting is performed by a loop mounted on the handheld trigger of the resectoscope in which Diathermy current is being passed. We all know that normal saline is a very good conductor of electricity (as it contains ions -- Na+ & Cl- ions). So if it is used while performing TURP, the diathermy current used in the procedure will cause electrolyte disassociation of normal saline and the current will not be localized in the loop and hence cutting of the tissue will not be proper. You can put up a question that the same can occur with the use of distilled water too. Distilled water can also conduct electricity-but the current used during TURF is not very strong and distilled water is not an as good conductor of electricity as Normal saline. (You must be aware that distilled water is a worse conductor of electricity than normal water.) There were also arguments that distilled water causes fluid overload and therefore should not be used in TURF True, distilled water causes fluid overload or TURP syndrome but this complication is not common Distilled water is being replaced by 1.5% glycine but still can be used for TURP (and is used in many centres when glycine is not available) Ref : Love & Bailey 25/e p1350, 1351