Postoperative urinary retention (POUR) is a common complication following colorectal surgery.1 Risk factors include older age, male sex, and benign prostatic hyperplasia (BPH).2 A disproportionate number of veterans have these risk factors compared to the civilian population.3 Alpha-1 adrenergic antagonists are the initial medical management of symptomatic BPH, and tamsulosin, which was approved by the Food and Drug Administration in 1997,4 is the most prescribed alpha-1 antagonist. This evidence concerns the gene PSMA6 and Urinary retention.