The use of intravesical lidocaine in severe IC was first reported in Sweden in 1989. Asklin et al., reported on one patient who received repeated intravesical instillations of lidocaine and achieved much relief13. Success with the treatment was subsequently reported for another patient in 199214. Surprisingly, there have been very few studies on the clinical efficacy of intravesical lidocaine in IC patients since then. To date, all studies involving intravesical lidocaine lack randomization or a control group. It is difficult to determine the influence of any existing placebo effect of intravesical instillations.