This study looks at how a medicine called *tamsulosin* (also known as Flomax) affects older men after surgery. It focuses on two main problems: post-operative urinary retention (POUR), which is when someone can't urinate on their own after a catheter is removed, and catheter-associated urinary tract infection (CAUTI), which is an infection caused by a catheter. A catheter is a tube that helps drain urine from the bladder. After surgery, it's used to help patients go to the bathroom. When it is taken out, some people cannot urinate, leading to discomfort and needing a temporary catheter again. This study checks if tamsulosin can help reduce POUR and CAUTI, which can otherwise cause discomfort, anxiety, and increase hospital costs.

• The study is for men aged 50 or older having surgery on their liver, gallbladder, pancreas, colon, or rectum.
• Participants must not have any prior tamsulosin use or be taking certain other medications.
• There is no mention of compensation or exact number of visits required for the study.