Dysuria with no cause, and nurse can't figure out what is wrong?

Consider I.C.: Interstitial cystitis, i.C. Is often difficult to diagnose. Usually the patient has seen several doctors prior to getting the diagnosis. It can cause pain with urination and especially pain with bladder filling. It can cause pain with intercourse and usually requires cystoscopy to help with the diagnosis. Diet has a pretty significant impact on it. Even without i.C., diet can affect dysuria.

Dysuria: Dysuria is the feeling of pain, burning, or discomfort upon urination. Although dysuria frequently indicates the presence of a urinary tract infection (UTI), it can have a variety of causes. Dysuria should always trigger a visit to a health-care professional for evaluation and diagnosis. http://www.emedicinehealth.com/dysuria/article_em.htm#dysuria_overview