The patient is a 71-year-old man with diabetes mellitus, hypertension, heart disease, peripheral vascular disease requiring bilateral below-knee amputation, prostate cancer treated with prostatectomy, and CKD stage 5 due to diabetic kidney disease. Diabetes mellitus was complicated by neurogenic bladder. After prostatectomy, the patient had significant postvoid residual urinary volumes of around 600 ml, as measured by ultrasound, and he was started on tamsulosin.