[False postvoid residual volume diagnosed by videourodynamics]

We present a case report of a young male patient, with a bilateral vesico renal reflux. The urodynamic study findings suggested the possibility of a non-neurogenic bladder-external spincter dissinergya producing a valuable residual volume. After biofeedback treatment, the dissinergia disappeaed, but residual volume persisted. The videourodynamic assessment allowed us the accurate diagnosis of a false residual volume, produced by the voiding of the refluxed urine from the ureters into the bladder.