Diagnosis

Fewer than half of the patients who have urinary incontinence tell their doctor about the problem. In many cases, patients simply feel that incontinence is part of the aging process. And, in spite of the commonness of this problem, two-thirds of doctors never ask their older patients if they experience incontinence.

It is important, however, for both the doctor and the patient to raise the issue.

Medical History

The first step in the diagnosis of incontinence is a detailed history. The doctor should ask questions about the patient's present and past medical conditions and patterns of urination. Patients should tell the doctor the following information:

• When the problem began
• Frequency of urination
• Amount of daily fluid intake
• Use of caffeine or alcohol
• Frequency and description of leakage or urine loss, including activity at the time, sensation of urge to urinate, and approximate volume of urine lost
• Frequency of urination during the night
• Whether the bladder feels empty after urinating
• Pain or burning during urination
• Problems starting or stopping the flow of urine
• Forcefulness of the urine stream
• Presence of blood, unusual odor or color in the urine
• A list of major surgeries with their dates, including pregnancies and deliveries, and other medical conditions
• Any medications being taken

A 2006 study suggested a simpler way of diagnosing incontinence using a test that asks 3 questions:

• During the last 3 months, have you leaked urine (even a small amount)?
• When did you leak urine? (During physical activity; when you could not reach the bathroom quickly enough; without physical activity or bladder urge.)
• When did you leak urine most often? (Physical activity; bladder urge; without or about equally with physical activity or bladder urge.)

Based on the patient’s answers, the “3IQ” test may help a doctor distinguish between urge and stress urinary incontinence. Voiding Diary. The patient might find it helpful to keep a diary for 3 to 4 days before the office visit. This diary, sometimes referred to as a voiding diary or log, should be a detailed record of:

• Daily eating and drinking habits
• The times and amounts of normal urination

For each incident of incontinence, the log should also detail:

• The amount of urine lost (the patient is often asked to catch and measure urine in a measuring cup during a 24-hour period)
• Whether the urge to urinate was present
• Whether the patient was involved in physical activity at the time

Physical Examination

The office visit should consist of a thorough physical examination, checking for abnormalities or enlargements in the rectal, genital, and abdominal areas that may cause or contribute to the problem.

Measuring Postvoid Residual Urine Volume

One of the important measurements for urinary incontinence is the postvoid residual urine volume (PVR). This is the amount of urine left in the bladder after urination:

• Normally, about 50 mL or less of urine is left
• More than 100 mL suggests an abnormality and requires further tests
• More than 200 mL is a definite sign of abnormalities

Use of a Catheter. The most common method for measuring PVR uses a catheter, which is inserted into the urethra after a few minutes of urination. The advantage of the catheter is that it can also collect urine for analysis.

Ultrasound. Ultrasound is useful in determining the volume of urine.

Cystometry

Cystometry measures the bladder's ability to retain urine at different capacities and pressures. It uses a catheter and can be performed at the same time as the PVR test.

Subtraction Cystometry. Although procedures vary, the basic steps for the technique are as follows:

• The patient empties the bladder as much as possible.
• Two catheters are inserted into the urethra until they reach the bladder. One is used to fill the bladder with water. The other is used to measure pressure. Another catheter is inserted into the rectum or vagina, which is used to measure abdominal pressure.
• While water is instilled through the tube into the bladder, the pressure in the bladder and abdomen are measured and the results are recorded in a computing device.
• During the process, the patient informs the doctor about any changes in the need to urinate, including the initial need to urinate, a normal desire to urinate, and a strong need to urinate.
• Often during this process, the patient is asked to cough, bounce up and down, or even walk in place. The patient may also be asked to strain as if he or she is having a bowel movement. This is called the Valsalva maneuver. The point at which leakage occurs during this action is called the Valsalva leak point pressure, which might be a useful measurement for determining treatment.
• When the urge to urinate is strong, the doctor stops this portion of the test.
• A calculation is then made using bladder and abdominal pressure measurements as well as volume and flow rate of the urine. The result provides the doctor with an assessment of detrusor contractions.

The detrusor muscles of a normal bladder will not contract during bladder filling. Severe contractions at low amounts of administered fluid (less than 200 mL) indicate urge incontinence. Stress incontinence is suspected when there is no significant increase in bladder pressure or detrusor muscle contractions during filling, but the patient experiences leakage if abdominal pressure increases.

Video Cystometry. Video cystometry combines a computer reading of bladder pressures and pictures of the bladder itself. It is most useful in cases where the more standard tests have not yielded satisfactory results.

Uroflowmetry

To determine whether the bladder is obstructed, the speed of urine flow is measured electronically using a test called uroflowmetry. The test involves the following steps:

• Patients are instructed not to urinate for several hours before the test and to drink plenty of fluids so they have a full bladder and a strong urge to urinate.
• To perform this test, a patient urinates into a special toilet equipped with a uroflowmeter.
• It is important that patients remain still while urinating to help ensure accuracy, and that they urinate normally and do not exert strain to empty their bladder or attempt to retard their urine flow.

Many factors can affect urine flow (such as straining or holding back because of self-consciousness) so experts recommend that the test be repeated at least twice.

Q[max]. The rate of urine flow is calculated as milliliters of urine passed per second (mL/s). At its peak, the flow rate measurement is recorded and referred to as the Q[max]. The higher the Q[max], the better the patient's flow rate. Men with a Q[max] of less than 12 mL/s have four times the risk for urinary retention than men with a stronger urinary flow.

The Q[max] measurement is sometimes used as the basis for determining the severity of obstruction and for judging the success of treatments. It is not very accurate, however, for a number of reasons:

• Urine flow varies widely among individuals as well as from test to test.
• The patient's age must be considered. Flow rate normally decreases as men age, so the Q[max] typically ranges from more than 25 mL/s in young men to less than 10 mL/s in elderly men.

The Q[max] level does not necessarily coincide with a patient's perceptions of the severity of his own symptoms.

Imaging Tests

Urethrocystoscopy. Urethrocystoscopy, also called cystourethroscopy or cystoscopy, detects structural abnormalities, inflammation of the bladder wall, or masses that might not show up on x-ray.

• The patient is given a light anesthetic, and the bladder is filled with water.
• Next, a thin flexible tube called a cystoscope is inserted through the urethra into the bladder.
• The end of the cystoscope contains a tiny microscope-like instrument.
• The doctor uses the cystoscope to look for abnormalities in the interior of the bladder.

The procedure has some risks. Complications are uncommon, but can include allergic response to the anesthetic, urinary tract infection, bleeding, and urine retention.

Intravenous Pyelogram. Intravenous pyelogram (IVP) may be used to diagnose urge incontinence. It is performed as follows:

• A dye is injected into the patient's vein and is processed by the kidneys.
• A series of x-ray pictures are taken of the kidneys, ureter, and bladder as the dye passes through them. This provides a dynamic picture of the relationship between the patient's urinary system and urinary functioning.

IVPs can detect structural abnormalities, urethral narrowing, or incomplete emptying of the bladder. This test should not be used on pregnant women or patients with kidney failure. There is a risk for an allergic reaction to standard dyes, although newer, less allergenic ones are becoming available.

Ultrasound. Ultrasound plays a role in many cases of incontinence. For example, it is useful for men with prostate problems. It is helpful in measuring urine volume in the bladder. Ultrasound may also be useful in many cases of female stress incontinence, by identifying abnormalities in the bladder neck, and in assessing the urinary tract before and after surgery. It also may eventually be useful in diagnosing detrusor instability.

Chain Cystogram. In cases of stress incontinence, a chain cystogram may also be performed. With this procedure, a beaded chain is positioned in the bladder and urethra. The x-ray image of the chain reveals the angle of the bladder neck. This test should not be performed on pregnant women.

Electrophysiologic Sphincter Testing

Electrophysiologic sphincter testing, also referred to as electromyography (EMG), evaluates two important factors:

• The function of the nerves serving the sphincter and pelvic floor muscles.
• The patient's ability to control these muscles.

Using a technique similar to that of an electrocardiogram, the doctor places electrodes on the affected areas to observe electrical activity in the muscles.

Urethral Pressure Profile

Urethral pressure profile is used to investigate urethral blockage. A probe is placed in the urethra to determine pressure at different points along this pathway during urination and the exact location of any obstruction in the urethra.