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.