<prompt> 60 yrs old male with poor stream of urine, post void residual urine is 400m1, bA hydronephrosis and prostate weighing 70 g. His urea is 120 and creat 3.5. Ideal next immediate step :Catheterize with Foley catheterbA PC NephrostomiesCT to rule out caMRI pelvis  <response>: Catheterize with Foley catheter Ref: Bailey and Love 25e p1316, 1349; CSDT I 3e p922 Catheterization is mandatory for acute urinary retention. Spontaneous voiding may return, but a catheter should be left indwelling.for 3 days while detruson tone returns.- CSDT I 3e This is a case of bladder outlet obstruction most likely due to BHP can also he due to ca. So the immediate next step is to drain the bladder a transurethral Foley catheter. If this fails suprapubic drainage can be done 