Postoperative urinary retention is a frequent complication of spinal surgeries and impacts a large portion of this population which results in increased morbidity as a result of increased number of catheterizations, urinary tract infections (UTIs) and prolonged hospital stays. With the addition of Tamsulosin, the investigators would anticipate a reduction in the incidence and duration of postoperative urinary retention and therefore a reduction in morbidity related to treatment of urinary retention as well as shortened hospital stays.