Intrathecal opioids decrease bladder function by causing dose-dependent suppression of detrusor contractility and decreased sensation of urge. Recovery of normal lower urinary tract function is significantly faster after intrathecal sufentanil than after morphine, and the recovery time is clearly dose dependent.

Bladder contractility returns much later than recovery of sensory function in sacral dermatomes (S3) when hyperbaric lidocaine combined with sufentanil is used for spinal anesthesia.