According to my doctor, the remedies you can buy over the counter only get rid of the symptoms, they do not get rid of the infection that comes with cystitis. Drinking a lot of water or cranberry juice certainly helps the symptoms and gradually the cystitis infection can die down on its own but it may take wuite some time. It can also just lie dormant and come back soon after again. To get rid of it properly and quickly, go to your doctor and he/she will prescribe an antibiotic. That together with the intake of lots of water and cranberry gets rid of it within a day or so totally. At least that is my experience. Hope you feel better soon.