Prevention of Post-operative Urinary Retention

The purpose of this study is to determine if tamsulosin (\"FLOMAX\") is effective in preventing post-operative urinary retention following abdominal surgery. Post-operative urinary retention is a common post-operative complication, occurring in up to 30% of patients undergoing abdominal surgery. It can be described as the inability to initiate urination or properly empty one\'s bladder following surgery. It is usually self-limited, but it requires the use of catheterization to empty the bladder in order to prevent further injury to the bladder or kidneys and to relief the discomfort of a full bladder. Tamsulosin is a medication that is commonly used in men with urinary symptoms related to an enlarged prostate. There is some evidence to suggest that it may also potentially be beneficial for preventing post-operative urinary retention. Therefore, in this research study, subjects scheduled for abdominal surgery will be randomly assigned to take either tamsulosin once-daily or placebo once-daily for one week leading up to surgery, and up to several days after surgery. Urinary function will be assessed and compared between these two treatments. The hypothesis is that tamsulosin will reduce the rate of postoperative urinary retention compared to placebo.