Diagnosis:
The attempt to define objective diagnostic criteria, based on cystoscopy under local or general anesthesia ,bladder distention with recording of bladder capacity  and/or presence of glomerulatoins or Hunner lesion, biopsy evaluated for inflammation , fibrosis, ulcer, mast cells etc. and urodynamic with registration of capacity, compliance and bladder stability, have been developed with significant outcomes. However, the results have been frustrating.  At present, it may be more meaningful to have broad clinical diagnosis, mainly on the basis of symptoms and exclusion of confusable diseases, then stratify patients by urodynamic, cystoscopic, histological and other tests on the bases of these findings for the results of treatment and prognosis. Phenotying the disorder by the presence of associated syndromes and diseased may be useful in this way.
Treatment:
Multimodal therapy remains the gold standard in the management of IC/ BPS. The stepwise of treatment from conservative, oral, intravesical/intramural, botulinum toxin (intramural)/neuromodulation and finally surgical therapy have been performed  with variable outcomes.
Principle of management:
The world acceptable diagnostic or treatment guideline are still ongoing due to lacking of high level evidence of efficacy. The approaching of patients is diverse reflect varying individual practice patterns and account for patient preference. An underling principle should be evidence based.
Due to the complexity of the IC/BPS such as  multifocal etiologie, co-morbidities, nature histories poor described, unpredictable treatment outcome (Wax vs. Wane ), the holistic approach by BPS (Bio-Psycho- Social) model will be the most valuable management for the disorder.