Undergoing a fluid infusion through the urethra for a Bultrasound (such as an ultrasound related to bladder function) is typically performed to better visualize the urethra or bladder. This procedure is generally safe and shouldn&39;t have any longterm impact on sexual activity. However, there may be slight discomfort or sensitivity in the urethra for a short period afterward, but these symptoms usually resolve within a few days.