Patient Inclusion Criteria

Adults aged 20 years old or above Patients with symptoms of frequency, urgency, nocturia, and/or bladder pain Proven to have glomerulations (at least grade 1) by cystoscopic hydrodistention under anesthesia in recent 1 year Free of active urinary tract infection Free of bladder outlet obstruction on enrolment Free of overt neurogenic bladder dysfunction and limitation of ambulation The patient, or his/her legally acceptable representative, has signed the written informed consent form

Patient Exclusion Criteria

Patients with severe cardiopulmonary disease such as congestive heart failure, arrhythmia, poorly controlled hypertension, or those unable to receive regular follow-up treatment Patients with bladder outlet obstruction on enrollment Patients with post-void residual >250mL Patients with an uncontrolled and confirmed diagnosis of acute urinary tract infection Patients with laboratory abnormalities at screening that include: ALT> 3 x upper limit of the normal range, AST> 3 x upper limit of the normal range; Patients with abnormal serum creatinine level > 2 x upper limit of the normal range Patients with any contraindication to urethral catheterization during treatment Female patients who are pregnant, lactating, or with child-bearing potential without contraception. Patients with any other serious disease considered by the investigator not in a condition to enter the trial Patients who had received intravesical onabotulinumtoxinA treatment for IC within the last 6 months Patients who participated in an investigational drug trial within 1 month before entering this study