Laboratory Studies
A urine sample should be collected for urinalysis and urine culture. Urinalysis may show up to three red blood cells (RBCs) per high-power field. More pronounced microhematuria or any history of gross hematuria should prompt (1) cystoscopy to evaluate the bladder and (2) computed tomography (CT) scanning to assess the upper urinary tract. Urine cytology may be considered if cystoscopy results are abnormal or for suspicion of bladder cancer. Elevated glucose levels on urinalysis results may suggest uncontrolled diabetes as an etiology of the urinary frequency.
Although some urologists feel that a bacterial colony count of 100/mL may be significant, especially when accompanied by symptoms, colony counts of 100,000/mL in a voided urine specimen (10,000/mL in men) confirms urinary tract infection in the presence of symptoms and should prompt treatment with antibiotics. Repeat urine cultures may be warranted for intermediate results.
The same bacteria on multiple urine cultures, even at low colony counts, may merit therapy. Ureaplasma urealyticum, Mycoplasma hominis, Gardnerella vaginalis, and Lactobacillus species may be present at low colony counts in urine cultures, and although that usually represents vaginal colonization with these organisms, treatment is recommended to rule out urethral colonization, especially with Ureaplasma species.
Pap smear results may reveal cervical malignancy, and this test should be performed if the patient has not had one in the past year. Usually, this has been performed by the gynecologist who referred the patient to the urologist. If the patient has not seen a gynecologist, a referral should be made to rule out gynecologic causes of the discomfort.
A pregnancy test may be indicated in women in the appropriate age group with an enlarged uterus or history of irregular menstrual cycles. This is particularly true if radiographic evaluation is planned.
Vaginal swabs for routine and viral, chlamydial, and gonococcal culture may be indicated. Again, usually these studies have been performed by the gynecologist. Potassium hydroxide preparation of vaginal secretions helps assess for fungal infection and, as with other tests, has usually been performed by the gynecologist.
Imaging Studies
Kidney/bladder ultrasound may be considered to help rule out other urological causes if associated symptoms and history suggest them. Pelvic ultrasonography is used to visualize the bladder and bladder neck–trigone and to evaluate the reproductive organs for masses in women and evaluate for a prostatic abscess in men.
Further radiologic studies may be indicated in select patients. Magnetic resonance imaging (MRI) is emerging as possibly superior to cystography in the identification of urethral diverticula. In addition, MRI may be useful in the identification of pelvic floor hypertonicity (manifested as shortened levator, increased posterior puborectalis angles, and decreased puborectal distances), which may be suggestive of interstitial cystitis/bladder pain syndrome. [9, 10]
Procedures
For suspicion of urethral diverticulum, cystography with a double-balloon catheter to occlude both the urethral opening and bladder neck may be performed. Urodynamic evaluation, including a cystometrogram and electromyelography of the urinary sphincter, uroflow, and determination of postvoid residual are performed to eliminate the possibility of a neurogenic unstable bladder, detrusor sphincter dyssynergia, or hyperactive pelvic floor musculature.
For suspicion of painful bladder syndrome (interstitial cystitis), cystourethroscopy with hydrodistention of the bladder under general anesthesia is diagnostic, revealing ulcerations or glomerulations and decreased bladder capacity in patients with interstitial cystitis. It is also may be therapeutic in some patients with interstitial cystitis.
For suspicion of bladder pathology, cystoscopy under anesthesia also allows an assessment for bladder masses, stones, or chronic inflammation.
Bladder biopsy is used to rule out carcinoma in situ. Eosinophilia and mast cells in bladder biopsy samples support the diagnosis of interstitial cystitis.
