A prospective, randomized, single-center double blind trial of Alvimopan versus placebo for improving patient outcomes and cost during radical cystectomy and urinary diversion will be performed. A randomized trial is necessary to control for all the known and unknown confounders associated with instituting this novel intervention into a surgical procedure. We will recruit 136 subjects (63 patients in each arm of the study per sample size calculation below, plus additional 10 subjects to account for drop outs). A control group will be administered a placebo in order to directly compare if the Alvimopan intervention is effective.