<prompt> A 60-year-old male with poor stream of urine, post void residual urine is 400 mL, bilateral hydronephrosis and prostate weighing 70 g. His urea is 120 and creatinine 3.5. Ideal next immediate step:Catheterize with Foley catheterBilateral PC nephrostomiesCT to rule out carcinomaMRI pelvis  <response>: Ans. a Catheterize with Foley catheterCauses of bilateral hydronephrosis: Posterior urethral valves Urethral atresia BPH cancer prostate Bladder neck stricture Urethral stricture PhimosisThe immediate next step in those cases is to put a Foleys catheter if possible. 