After the Urodynamic Test

You may have mild discomfort for a few hours after these tests. Drinking two 8-ounce glasses of water each hour for 2 hours should help. Ask your doctor whether you can take a warm bath. If not, you may be able to hold a warm, damp washcloth over the urethral opening to relieve the discomfort.

Your doctor may give you an antibiotic to take for 1 or 2 days to prevent an infection. If you have signs of infection--including pain, chills, or fever--call your doctor at once.

source: http://kidney.niddk.nih.gov/kudiseases/pubs/urodynamic/index.htm