Because patient presentation and symptoms vary widely, all other etiologies must be excluded. The most worrisome would be that of a malignancy or other systemic condition for which treatment would be needed. IC/BPS thus remains a diagnosis of exclusion. Investigations should routinely be directed to exclude bacterial cystitis, neurogenic and nonneurogenic overactive bladder (OAB), endometriosis, bladder cancer, urethral diverticulum, and pelvic floor dysfunction. Defining IC/BPS has been extremely controversial, and to date, there remains considerable disagreement among experts. In 1987 and 1988, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) developed a research definition for IC/BPS in order to provide homogenous groups of patients that may be compared to one another in clinical studies. However, experts in female urology and urogynecology have found this definition to be far too restrictive, and as many as 60% of patients with IC/BPS were being excluded (2). According to the International Continence Society, IC/BPS should be suspected in anyone with symptoms of suprapubic pain related to bladder filling, accompanied by urinary frequency and urgency, in the absence of urinary infection or other pathology (4). A similar definition was adopted by the American Urological Association (AUA) in their recent guidelines, although a more general “unpleasant sensation (pain, pressure, discomfort)” relating to the bladder was included (5). The European Society for the Study of IC/BPS (ESSIC) has developed specific diagnostic criteria that are based on a combination of urinary symptoms and bladder findings during cystoscopic evaluation. Although the vague inclusion criteria and overlapping taxonomy may be confusing, treatment should generally be directed toward the patient’s symptoms and any other coexisting conditions. Epidemiologic studies have shown increased rates of irritable bowel syndrome, fibromyalgia, migraine headaches, and anxiety (6).

Symptoms of IC/BPS are extremely variable and may present as mild irritative symptoms to severe symptoms refractory to all standard therapies. Acknowledging and treating the disease early often leads to rapid improvement in symptoms; thus, recognizing IC/BPS early so that therapy can be initiated is extremely important.

The diagnosis of IC/BPS begins with a complete and thorough history. Onset of symptoms may be days, weeks, or even months. Often patients have been clinically diagnosed with urinary tract infections despite negative cultures. Other misdiagnoses include endometriosis, fibroids, or other pelvic disorders, and some have even undergone surgery for them (7). A full dietary and fluid history is useful, as certain foods and drinks may exacerbate IC/BPS symptoms (8). A voiding diary provides objective evidence of daytime and nighttime frequency, and pain symptoms can be recorded with these as well. Baseline and sequential voiding diaries and symptom questionnaires allow one to determine the impact of various treatments for IC/BPS. The O’Leary-Sant Interstitial Cystitis Symptoms Index/Interstitial Cystitis Problem Index (ICSI/ICPI) and Pain, Urgency, Frequency scales (PUF) are commonly used (Table 27.1). For the pain component, a 10-point visual analog scale (VAS) and brief descriptor of pain location and quality is often all that is needed. It must be emphasized that these questionnaires assess baseline symptoms and treatment response but do not diagnose IC/BPS per se.

A physical examination that includes a thorough pelvic and neurologic examination should be performed. The female pelvic examination should include evaluation for tenderness of the anterior vaginal wall and levator muscles, the ability to contract and relax the pelvic floor muscles, and the degree of pelvic relaxation. A high-tone pelvic floor can contribute to a large portion of patient symptomatology (9). Urethral fullness, tenderness, or expression of pus may suggest a urethral diverticulum requiring further workup. Vaginal pH and wet-mount microscopic exam is beneficial in ruling out vaginitis or infectious etiology. Careful attention should be paid to vulvar or vestibular sensitivity, herpetic vesicles, atrophic vaginal mucosa, and any other cutaneous findings. A rectal examination can rule out any rectal abnormalities or masses, and in men, not only should the prostate be palpated but the tenderness or spasm of the pelvic floor muscles should also be assessed because this is a common cause of pelvic pain and voiding dysfunction. A urinalysis and urine culture should be performed to exclude active infection. Sterile pyuria should prompt staining for acid-fast bacilli to rule out genitourinary tuberculosis. If microscopic or gross hematuria is present, an initial workup including computerized tomography (CT) urography and cystoscopy is required in order to evaluate for bladder cancer or stone disease.

In patients with primarily urinary urgency, frequency, or incontinence, a trial of anticholinergics may cause symptoms to subside supporting the diagnosis of OAB. If symptoms persist, if pelvic pain worsens with bladder filling, or if severe dysuria is present, a cystoscopic evaluation is warranted. IC was first described as a distinct ulcer seen on cystoscopic examination (1). This lesion is typically red, raised, and friable and can be seen during cystoscopy without hydrodistention. The lesion is difficult to distinguish from carcinoma in situ, and a biopsy with cauterization of the lesion is required to confirm its benign nature. Although less than 15% of patients diagnosed with IC/BPS have an ulcer in their bladder, symptom improvement with fulguration can be remarkable (10). Ulcerative patients are typically older and have more severe bladder-associated pain and a smaller anesthetic bladder capacity (11).

In patients in whom a diagnosis of IC/BPS is highly suspected clinically, cystoscopy with hydrodistention under anesthesia may reveal petechial hemorrhages and glomerulations, which are found in over 90% of women with the syndrome. However, the presence of petechial hemorrhages alone is not diagnostic, as they can also be seen in normal men and women (12). A computerized cystometrogram may also be performed to look for uninhibited contractions and to determine the functional bladder capacity. Some investigators have suggested the use of the potassium sensitivity test (PST) to diagnose IC/BPS (13). The PST is based on the hypothesis that there is increased epithelial permeability in the bladder of IC patients and potassium is very irritating to the exposed tissue. However, a significant false-positive rate exists, and many patients will eventually be diagnosed with a normal bladder (14). Additionally, 17% of women with IC/BPS may have a negative test (15). For these reasons, PST is not currently recommended during evaluation and diagnosis.