@rashida
A cystoscopy can miss interstitial cystitis (IC) if it's performed in an office and doesn't involve hydrodistension. IC is also known as bladder pain syndrome (BPS), and a cystoscopy can help identify abnormalities in the bladder that are typical of IC/BPS. However, the bladder needs to be filled with high pressure during a cystoscopy to see these abnormalities, and this can be painful if the patient isn't anesthetized. In addition, in-office cystoscopies may not be able to identify glomerulations, which are pinpoint sites of bleeding on the bladder wall that can be a sign of IC/BPS.
The Interstitial Cystitis Association says that cystoscopy with hydrodistension is no longer the standard method for diagnosing IC/BPS. However, some clinicians still consider cystoscopy to be mandatory, and the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) has established cystoscopic discovery of glomerulations or Hunner lesions as a diagnostic criterion for IC/BPS. However, many experts agree that the absence of these findings doesn't rule out IC/BPS.