interstitial cystitis
"I could barely function after 2pm until I went on this medicine.  I was diagnosed with Interstitial Cystitis in August-it was devastating.  My quality of life was horrible--pain through the roof and urgency.  I could barely get my kids to school every day.  After 1 day of 25 mg Amytriptiline at bedtime, my pain virtually disappeared.  It saved my life."