The best option for assessing postvoid residual volume is a bladder scanner. It is noninvasive and accurate. Intermittent catheterization can be performed in the absence of a bladder scanner, but it increases the patient’s risk for infection, so is not the first choice. Instructing the patient to void again immediately after is not helpful, especially if there is a pathophysiologic reason for the urinary retention. Applying pressure to the patient’s suprapubic area while the patient is on a bedpan may cause damage if the patient’s urinary retention is due to an obstruction.