Urinary incontinence

Definition

Urinary incontinence is unintentional loss of urine that is sufficient enough in frequency and amount to cause physical and/or emotional distress in the person experiencing it.

Description

Approximately 13 million Americans suffer from urinary incontinence. Women are affected by the disorder more frequently than are men; one in 10 women under age 65 suffers from urinary incontinence. A study published in late 2002 found that between 21% and 29% of adult women in the workforce reported at least one episode of urinary incontinence each month. Older Americans, too, are more prone to the condition. Twenty percent of Americans over age 65 are incontinent. In general, the condition is underrecognized and undertreated.

There are five major categories of urinary incontinence: overflow, stress, urge, functional, and reflex:

• Overflow incontinence. Overflow incontinence is caused by bladder dysfunction. Individuals with this type of incontinence have an obstruction to the bladder or urethra, or a bladder that doesn't contract properly. As a result, their bladders do not empty completely, and they have problems with frequent urine leakage.
• Stress incontinence. Stress incontinence occurs when an individual involuntarily loses urine after pressure is placed on the abdomen (i.e., during exercise , sexual activity, sneezing, coughing, laughing, or hugging).
• Urge incontinence. Urge incontinence occurs when a person feels a sudden need to urinate and cannot control the urge to do so. As a consequence, urine is involuntarily lost before the individual can get to the toilet.
• Functional incontinence. Individuals who have control over their own urination and have a fully functioning urinary tract, but cannot make it to the bathroom in time due to a physical or cognitive disability, are functionally incontinent. These individuals may suffer from arthritis, Parkinson's disease, multiple sclerosis , or Alzheimer's disease.
• Reflex incontinence. Individuals with reflex incontinence lose control of their bladder without warning. They typically suffer from neurological impairment.

In some cases, an individual may develop short-term or acute incontinence. Acute incontinence may occur as a symptom or byproduct of illness, as a side effect of medication, or as a result of dietary intake. The condition is typically easily resolved once the cause is determined and addressed.

Causes & symptoms

Urinary incontinence can be caused by a wide variety of physical conditions, including:

• Childbirth . Childbirth can stretch the pelvic muscles and cause the bladder to lose some support from surrounding muscles, resulting in stress incontinence.
• Dysfunction of the bladder and/or the urinary sphincter. In a continent individual, as the bladder contracts, the outlet that releases urine into the urethra (bladder sphincter) opens and urine exits the body. In individuals with overflow incontinence, bladder contractions and dilation of the sphincter do not occur at the same time.
• Enlarged prostate. In men, an enlarged prostate gland can obstruct the bladder, causing overflow incontinence.
• Hysterectomy or other gynecological surgery. Any surgery involving the urogenital tract runs the risk of damaging or weakening the pelvic muscles and causing incontinence.
• Menopause. The absence of estrogen in the postmenopausal woman can cause the bladder to drop, or prolapse.
• Neurological conditions. The nervous system sends signals to the bladder telling it when to start and stop emptying. When the nervous system is impaired, incontinence may result. Neurological conditions such as multiple sclerosis, stroke , spinal cord injuries, or a brain tumor may cause the bladder to contract involuntarily, expelling urine without warning, or to cease contractions completely, causing urinary retention.
• Obesity. Persons who are overweight have undue pressure placed on their bladder and surrounding muscles.
• Obstruction. A blockage at the bladder outlet may permit only small amounts of urine to pass, resulting in urine retention and subsequent overflow incontinence. Tumors, calculi, and scar tissue can all block the flow of urine. A urethral stricture, or narrow urethra caused by scarring or inflammation, may also result in urine retention.

Acute incontinence is a temporary condition caused by a number of factors, including:

• Bladder irritants. Substances in the urine that irritate the bladder may cause the bladder muscle to malfunction. The presence of a urinary tract infection and the ingestion of excess caffeine can act as irritants. Highly concentrated urine resulting from low fluid intake may also irritate the bladder.

• Constipation . Constipation can cause incontinence in some individuals. Stool that isn't passed presses against the bladder and urethra, triggering urine leakage.
• Illness or disease. Diabetes can greatly increase urine volume, making some individuals prone to incontinence. Other illnesses may temporarily impair the ability to recognize and control the urge to urinate, or to reach the toilet in time to do so.
• Medications and alcohol. Medications that sedate, such as tranquilizers and sleeping pills, can interfere with the proper functioning of the urethral nerves and bladder. Both sedatives and alcohol can also impair an individual's ability to recognize the need to urinate, and act on that need in a timely manner. Other medications such as diuretics, muscle relaxants, and blood pressure medication can also affect bladder function.
• Surgery. Men who undergo prostate surgery can suffer from temporary stress incontinence as a result of damage to the urethral outlet.

Diagnosis

Urinary incontinence may be diagnosed by a general practitioner, urologist, or gynecologist. If the patient is over age 65, a gerontologist may diagnose and treat the condition. A thorough medical history and physical examination is typically performed, along with specific diagnostic testing to determine the cause of the incontinence. Diagnostic testing may include x rays, ultrasound, urine tests, and a physical examination of the pelvis. It may also include a series of exams that measure bladder pressure and capacity and the urinary flow (urodynamic testing). The patient may also be asked to keep a diary to record urine output, frequency, and any episodes of incontinence over a period of several days or a week.

Treatment

Adjusting dietary habits and avoiding acidic and spicy foods, alcohol, caffeine, and other bladder irritants can help to prevent urinary leaking. The patient should eat recommended amounts of whole grains, fruits, and vegetables to avoid constipation. Bladder training, used to treat urge incontinence, can also be a useful treatment tool. The technique involves placing a patient on a toileting schedule. The time interval between urination is then gradually increased until an acceptable time period between bathroom breaks is consistently achieved.

Therapies designed to strengthen the pelvic muscles are also recommended for the treatment of urinary incontinence. Pelvic toning exercises, known as Kegel or PC muscle exercises, can alleviate stress incontinence in both men and women. These exercises involve repeatedly tightening the muscles of the pelvic floor.

Biofeedback techniques can teach incontinent patients to control the urge to urinate. Biofeedback uses sensors to monitor temperature and muscle contractions in the vagina to help incontinent patients learn to increase their control over the pelvic muscles.

An infusion, or tea, of horsetail (Equisetum arvense ), agrimony (Agrimonia eupatoria ), and sweet sumac (Rhus aromatica ) may be prescribed by an herbalist or naturopath to treat stress and urge incontinence. These herbs are natural astringents and encourage toning of the digestive and urinary tracts. Other herbs, such as urtica or stinging nettle (Urtica urens ), plantain (Plantago major ), or maize (Zea mays ) may be helpful. Homeopathic remedies may include pulsatilla and causticum. Chinese herbalists might recommend golden lock tea, a mixture of several herbs that helps the body retain fluids.

Allopathic treatment

There are numerous invasive and noninvasive treatment options for urinary incontinence:

• Behavior modification therapy. Behavior modification is a psychological approach to the treatment of urinary incontinence in which patients gradually increase the length of the time interval between voidings and "retrain" the bladder in other ways. It is reported to be highly effective in treating urge incontinence.

• Collagen injections. Collagen injected in the tissue surrounding the urethra can provide urethral support for women suffering from stress incontinence.
• External occlusive devices. A new single-use disposable urethral cap is available without a prescription as of late 2002 for women suffering from stress urinary incontinence. The cap is noninvasive and appears to be quite effective in managing incontinence.
• Inflatable urethral insert. Sold under the tradename Reliance, this disposable incontinence balloon for women is inserted into the urethra and inflated to prevent urine leakage.
• Intermittent urinary catheterization. This procedure involves the The periodic insertion of a catheter into a patient's bladder to drain urine from the bladder into an attached bag or container.
• Medication. Estrogen hormone replacement therapy can help improve pelvic muscle tone in postmenopausal women. Other medications, including flurbiprofen, capsaicin and botulinum toxin, are sometimes prescribed to relax the bladder muscles or to tighten the urethral sphincter. As of late 2002, newer medications for the treatment of urinary incontinence are undergoing clinical trials. One of these drugs, duloxetine, differs from present medications in targeting the central nervous system's control of the urge to urinate rather than the smooth muscle of the bladder itself.
• Perineal stimulation. Perineal stimulation is used to treat stress incontinence. The treatment uses a probe to deliver a painless electrical current to the perineal area muscles. The current tones the muscle by contracting it.
• Permanent catheterization. A permanent, or indwelling, catheter may be prescribed for chronic incontinence that doesn't respond to other treatments.
• Sacral nerve stimulation (SNS). Also known as sacral neuromodulation, SNS is a procedure in which a surgeon implants a device that sends continuous stimulation to the sacral nerves that control the urinary sphincter. The FDA approved sacral nerve stimulation for the treatment of urinary urge incontinence in 1997 and for urinary frequency in 1999.
• Surgery. Bladder neck suspension surgery is used to correct female urinary stress incontinence. Bladder enlargement surgery may be recommended to treat incontinent men and women with unusually small bladders.
• Urinary sphincter implant. An artificial urinary sphincter may be used to treat incontinence in men and women with urinary sphincter impairment.
• Vaginal inserts. Devices constructed of silicone or other pliable materials can be inserted into a woman's vagina to support the urethra.

Expected results

Left untreated, incontinence can cause physical and emotional upheaval. Individuals with long-term incontinence suffer from urinary tract infections , and skin rashes and sores. Incontinence can also affect their self-esteem and cause depression and social withdrawal. They frequently stop participating in physical activities they once enjoyed because of the risk of embarrassing "accidents." However, with the wide variety of treatment options for incontinence available today, the prognosis for incontinent patients is promising. If incontinence cannot be stopped, it can be improved in the majority of cases.

Prevention

Women who are pregnant or who have gone through childbirth can reduce their risk for stress incontinence by strengthening their perineal area muscles with Kegel exercises. Men who have undergone prostate surgery may also benefit from pelvic muscle exercises. Men and women should consult with their doctor before initiating any type of exercise program.

Resources

BOOKS

Blaivas, Jerry. Conquering Bladder and Prostate Problems: The Authoritative Guide for Men and Women. New York, NY: Plenum, 1998.

"Urinary Incontinence." Section 17, Chapter 215 in The Merck Manual of Diagnosis and Therapy, edited by Mark H. Beers, MD, and Robert Berkow, MD. Whitehouse Station, NJ: Merck Research Laboratories, 1999.

PERIODICALS

Amundsen, C. L., and G. D. Webster. "Sacral Neuromodulation in an Older, Urge-Incontinent Population." American Journal of Obstetrics and Gynecology 187 (December 2002): 1462–1465.

Bachmann, G., and B. Wiita. "External Occlusive Devices for Management of Female Urinary Incontinence." Journal of Women's Health (Larchmont) 11 (November 2002): 793–800.

Burgio, K. L. "Influence of Behavior Modification on Overactive Bladder." Urology 60 (November 2002): (5 Suppl. 1): 72–76.

Burgio, K. L., P. S. Goode, J. L. Locher, et al. "Behavioral Training With and Without Biofeedback in the Treatment of Urge Incontinence in Older Women: A Randomized Controlled Trial." Journal of the American Medical Association 288 (November 13, 2002): 2293–2299.

Haeusler, G., H. Leitich, M. van Trotsenburg, et al. "Drug Therapy of Urinary Urge Incontinence: A Systematic Review." Obstetrics and Gynecology 100 (November 2002) (5 Pt 1): 1003–1016.

Palmer, M. H., and S. Fitzgerald. "Urinary Incontinence in Working Women: A Comparison Study." Journal of Women's Health (Larchmont) 11 (December 2002): 879–888.

Sandroff, Ronni. "Urgent Matters: Incontinence is Treatable, If Only Women Would Talk About It." American Health for Women 16, no. 8 (Oct 1997): 28–30.

Viktrup, L. "Female Stress and Urge Incontinence in Family Practice: Insight Into the Lower Urinary Tract." International Journal of Clinical Practice 56 (November 2002): 694–700.

Yoshimura, N., and M. B. Chancellor. "Current and Future Pharmacological Treatment for Overactive Bladder." Journal of Urology 168 (November 2002): 1897–1913.

ORGANIZATIONS

American Foundation for Urologic Disease. 1128 North Charles Street, Baltimore, MD 21201. (800) 242-2383. http://www.afud.org/.

American Urological Association (AUA). 1120 North Charles Street, Baltimore, MD 21201. (410) 727-1100. <www.auanet.org>.

Center for Biologics Evaluation and Research (CBER), U. S. Food and Drug Administration (FDA). 1401 Rockville Pike, Rockville, MD 20852-1448. (800) 835-4709 or (301) 827-1800. <www.fda.gov/cber>.

National Association for Continence. 2650 East Main Street, Spartanburg, SC 29307. (800) 252-3337. http://www.nafc.org.

National Kidney and Urologic Diseases Information Clearing-house. 3 Information Way, Bethesda, MD 20892-3580. (800) 891-5390.

Paula Ford-Martin

Rebecca J. Frey, PhD

KEY TERMS

Calculi (singular, calculus)

—Mineral deposits that can form a blockage in the urinary system.

Urinary Incontinence

Definition

Urinary incontinence is unintentional loss of urine that is sufficient enough in frequency and amount to cause physical and/or emotional distress in the person experiencing it.

Description

Approximately 13 million Americans suffer from urinary incontinence. Women are affected by the disorder more frequently than are men; one in 10 women under age 65 suffers from urinary incontinence. A study published in late 2002 found that between 21% and 29% of adult women in the workforce reported at least one episode of urinary incontinence each month. Older Americans, too, are more prone to the condition. Twenty percent of Americans over age 65 are incontinent. In general, the condition is underrecognized and undertreated.

There are five major categories of urinary incontinence: overflow, stress, urge, functional, and reflex.

• Overflow incontinence. Overflow incontinence is caused by bladder dysfunction. Individuals with this type of incontinence have an obstruction to the bladder or urethra, or a bladder that doesn't contract properly. As a result, their bladders do not empty completely, and they have problems with frequent urine leakage.
• Stress incontinence. Stress incontinence occurs when an individual involuntarily loses urine after pressure is placed on the abdomen (i.e., during exercise, sexual activity, sneezing, coughing, laughing, or hugging).
• Urge incontinence. Urge incontinence occurs when an individual feels a sudden need to urinate, and cannot control the urge to do so. As a consequence, urine is involuntarily lost before the individual can get to the toilet.
• Functional incontinence. Individuals who have control over their own urination and have a fully functioning urinary tract, but cannot make it to the bathroom in time due to a physical or cognitive disability, are functionally incontinent. These individuals may suffer from arthritis, Parkinson's disease, multiple sclerosis, or Alzheimer's disease.
• Reflex incontinence. Individuals with reflex incontinence lose control of their bladder without warning. They typically suffer from neurological impairment.

In some cases, an individual may develop short-term or acute incontinence. Acute incontinence may occur as a symptom or by-product of illness, as a side effect of medication, or as a result of dietary intake. The condition is typically easily resolved once the cause is determined and addressed.

Causes and symptoms

Urinary incontinence can be caused by a wide variety of physical conditions, including:

• Childbirth. Childbirth can weaken the pelvic muscles and cause the bladder to lose some support from surrounding muscles, resulting in stress incontinence.
• Dysfunction of the bladder and/or the urinary sphincter. In a continent individual, as the bladder contracts, the outlet that releases urine into the urethra (bladder sphincter) opens and urine exits the body. In individuals with overflow incontinence, bladder contractions and dilation of the sphincter do not occur at the same time.
• Enlarged prostate. In men, an enlarged prostate gland can obstruct the bladder, causing overflow incontinence.
• Hysterectomy or other gynecological surgery. Any surgery involving the urogenital tract runs the risk of damaging or weakening the pelvic muscles and causing incontinence.
• Menopause. The absence of estrogen in the postmenopausal woman can cause the bladder to drop, or prolapse.
• Neurological conditions. The nervous system sends signals to the bladder telling it when to start and stop emptying. When the nervous system is impaired, incontinence may result. Neurological conditions such as multiple sclerosis, stroke, spinal cord injuries, or a brain tumor may cause the bladder to contract involuntarily, expelling urine without warning, or to cease contractions completely, causing urinary retention.
• Obesity. Individuals who are overweight have undue pressure placed on their bladder and surrounding muscles.
• Obstruction. A blockage at the bladder outlet may permit only small amounts of urine to pass, resulting in urine retention and subsequent overflow incontinence. Tumors, calculi, and scar tissue can all block the flow of urine. A urethral stricture, or narrow urethra caused by scarring or inflammation, may also result in urine retention.

Acute incontinence is a temporary condition caused by a number of factors, including:

• Bladder irritants. Substances in the urine that irritate the bladder may cause the bladder muscle to malfunction. The presence of a urinary tract infection and the ingestion of excess caffeine can act as irritants. Highly concentrated urine resulting from low fluid intake may also irritate the bladder.
• Constipation. Constipation can cause incontinence in some individuals. Stool that isn't passed presses against the bladder and urethra, triggering urine leakage.
• Illness or disease. Diabetes can greatly increase urine volume, making some individuals prone to incontinence. Other illnesses may temporarily impair the ability to recognize and control the urge to urinate, or to reach the toilet in time to do so.
• Medications and alcohol. Medications that sedate, such as tranquilizers and sleeping pills, can interfere with the proper functioning of the urethral nerves and bladder. Both sedatives and alcohol can also impair an individual's ability to recognize the need to urinate, and act on that need in a timely manner. Other medications such as diuretics, muscle relaxants, and blood pressure medication can also affect bladder function.
• Surgery. Men who undergo prostate surgery can suffer from temporary stress incontinence as a result of damage to the urethral outlet.

Diagnosis

Urinary incontinence may be diagnosed by a general practitioner, urologist, or gynecologist. If the patient is over age 65, a geriatrician may diagnose and treat the condition. A thorough medical history and physical examination is typically performed, along with specific diagnostic testing to determine the cause of the incontinence. Diagnostic testing may include x rays, ultrasound, urine tests, and a physical examination of the pelvis. It may also include a series of exams that measure bladder pressure and capacity and the urinary flow (urodynamic testing). The patient may also be asked to keep a diary to record urine output, frequency, and any episodes of incontinence over a period of several days or a week.

Treatment

There are numerous invasive and noninvasive treatment options for urinary incontinence:

• Behavior modification therapy. Behavior modification is a psychological approach to the treatment of urinary incontinence in which patients gradually increase the length of the time interval between voidings and "retrain" the bladder in other ways. It is reported to be highly effective in treating urge incontinence.
• Biofeedback. The use of sensors to monitor temperature and muscle contractions in the vagina to help incontinent patients learn to control their pelvic muscles.
• Collagen injections. Collagen injected in the tissue surrounding the urethra can provide urethral support for women suffering from stress incontinence.
• External occlusive devices. A new single-use disposable urethral cap is available without a prescription as of late 2002 for women suffering from stress urinary incontinence. The cap is noninvasive and appears to be quite effective in managing incontinence.
• Inflatable urethral insert. Sold under the trade name Reliance, this disposable incontinence balloon for women is inserted into the urethra and inflated to prevent urine leakage.
• Intermittent urinary catheterization. The periodic insertion of a catheter into a patient's bladder to drain urine from the bladder into an attached bag or container.

• Medication. Estrogen hormone replacement therapy can help improve pelvic muscle tone in postmenopausal women. Other medications, including flurbiprofen, capsaicin and botulinum toxin, are sometimes prescribed to relax the bladder muscles or to tighten the urethral sphincter. As of late 2002, newer medications for the treatment of urinary incontinence were undergoing clinical trials. One of these drugs, duloxetine, differs from present medications in targeting the central nervous system's control of the urge to urinate rather than the smooth muscle of the bladder itself.
• Pelvic toning exercises. Exercises to tone the pelvic muscle can help alleviate stress incontinence in both men and women. These exercises involve tightening the muscles of the pelvic floor, and are also known as Kegel or PC muscle exercises.
• Perineal stimulation. Perineal stimulation is used to treat stress incontinence. The treatment uses a probe to deliver a painless electrical current to the perineal area muscles. The current tones the muscle by contracting it.
• Permanent catheterization. A permanent, or indwelling, catheter may be prescribed for chronic incontinence that doesn't respond to other treatments. A Foley catheter is usually used for urinary catheterization. One end is inserted through the urethra and into the bladder, and the external end is attached to a plastic reservoir bag that the patient may wear on the leg. A second alternative is a permanent catheter, called a suprapubic tube, surgically inserted into the bladder. The tube exits the body through the abdomen near the pubic bone, where it is attached to a drainage bag. As infection may result, this treatment should be reevaluated periodically, and the possibility of alternative treatment addressed.
• Sacral nerve stimulation (SNS). Also known as sacral neuromodulation, SNS is a procedure in which a surgeon implants a device that sends continuous stimulation to the sacral nerves that control the urinary sphincter. The FDA approved sacral nerve stimulation for the treatment of urinary urge incontinence in 1997 and for urinary frequency in 1999.
• Surgery. Bladder neck suspension surgery is used to correct female urinary stress incontinence. Surgical techniques such as the Marshall-Marchetti-Krantz and Burch procedures use sutures to raise and support the bladder neck and urethra. A sling procedure, which uses a strip of biocompatible material or the patient's own muscle or tissue as a supportive sling under the urethra and bladder neck, may also be used to treat stress incontinence. Bladder enlargement surgery may be recommended to treat incontinent men and women with unusually small bladders.
• Urinary sphincter implant. An artificial urinary sphincter may be used to treat incontinence in men and women with urinary sphincter impairment.
• Vaginal inserts. Devices constructed of silicone or other pliable materials that can be inserted into a woman's vagina to support the urethra.

Prognosis

Left untreated, incontinence can cause physical and emotional upheaval. Individuals with long-term incontinence suffer from urinary tract infections, and skin rashes and sores. Incontinence can also affect their self-esteem and cause depression and social withdrawal. They frequently stop participating in physical activities they once enjoyed because of the risk of embarrassing "accidents." However, with the wide variety of treatment options for incontinence available today, the prognosis for incontinent patients is promising. If incontinence cannot be stopped, it can be improved in the majority of cases.

KEY TERMS

Bladder neck— The place where the urethra and bladder join.

Bladder sphincter— The outlet that releases urine into the urethra.

Calculi (singular, calculus)— Mineral deposits that can form a blockage in the urinary system.

Occlusive— Closing off. One of the newest treatments for stress urinary incontinence in women is an external occlusive single-use cap that covers the urethral opening.

Perineal area— The genital area between the vulva and anus in a woman, and between the scrotum and anus in a man.

Sacral nerves— The five pairs of nerves that arise from the lowermost segments of the spinal cord and control bladder, bowel, and pelvic functions. Stimulation of the sacral nerves by an implanted device is a newer treatment for urinary incontinence.

Prevention

Women who are pregnant or who have gone through childbirth can reduce their risk for stress incontinence by strengthening their perineal area muscles with Kegel exercises. Men who have undergone prostate surgery may also benefit from pelvic muscle exercises. Men and women should consult with their doctor before initiating any type of exercise program.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Urinary Incontinence." Section 17, Chapter 215 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

PERIODICALS

Amundsen, C. L., and G. D. Webster. "Sacral Neuromodulation in an Older, Urge-Incontinent Population." American Journal of Obstetrics and Gynecology 187 (December 2002): 1462-1465.

Bachmann, G., and B. Wiita. "External Occlusive Devices for Management of Female Urinary Incontinence." Journal of Women's Health (Larchmont) 11 (November 2002): 793-800.

Burgio, K. L. "Influence of Behavior Modification on Overactive Bladder." Urology 60, no.5, Supplement 1 (November 2002): 72-76.

Burgio, K. L., P. S. Goode, J. L. Locher, et al. "Behavioral Training With and Without Biofeedback in the Treatment of Urge Incontinence in Older Women: A Randomized Controlled Trial." Journal of the American Medical Association 288 (November 13, 2002): 2293-2299.

Haeusler, G., H. Leitich, M. van Trotsenburg, et al. "Drug Therapy of Urinary Urge Incontinence: A Systematic Review." Obstetrics and Gynecology 100, no. 5, Part 1 (November 2002): 1003-1016.

Palmer, M. H., and S. Fitzgerald. "Urinary Incontinence in Working Women: A Comparison Study." Journal of Women's Health (Larchmont) 11 (December 2002): 879-888.

Viktrup, L. "Female Stress and Urge Incontinence in Family Practice: Insight Into the Lower Urinary Tract." International Journal of Clinical Practice 56 (November 2002): 694-700.

Yoshimura, N., and M. B. Chancellor. "Current and Future Pharmacological Treatment for Overactive Bladder." Journal of Urology 168 (November 2002): 1897-1913.

ORGANIZATIONS

American Foundation for Urologic Disease. 1128 North Charles St., Baltimore, MD 21201. (800) 242-2383. 〈http://www.afud.org〉.

American Urological Association (AUA). 1120 North Charles Street, Baltimore, MD 21201. (410) 727-1100. 〈www.auanet.org〉.

Center for Biologics Evaluation and Research (CBER), U. S. Food and Drug Administration (FDA). 1401 Rockville Pike, Rockville, MD 20852-1448. (800) 835-4709 or (301) 827-1800. 〈www.fda.gov/cber〉.

National Association for Continence. P.O. Box 8310, Spartanburg, SC 29305-8310. (800) 252-3337. 〈http://www.nafc.org〉.

National Kidney and Urologic Diseases Information Clearinghouse. 3 Information Way, Bethesda, MD 20892-3580. (800) 891-5390.

URINARY INCONTINENCE

Urinary incontinence may affect as many as two hundred million people around the world. Urinary incontinence is not well understood by those affected, or by health care workers. It is not a dangerous condition, but it has a huge influence on the sufferer’s quality of life. The International Continence Society, established in 1970, defines urinary incontinence as a condition where involuntary loss of urine is a social or hygienic problem and is objectively demonstrated.

Prevalence

Reports of the prevalence of urinary incontinence in women vary because of differences in the definition of urinary incontinence, the study samples, and underreporting due to variation in the methodology of surveys. The condition is more common in women. Systematic reviews conclude that there is a community prevalence of 20 to 30 percent in young adults, 30 to 40 percent in middle-aged women and 30 to 50 percent in elderly women. In long-term care institutions, the prevalence is higher. If incontinence severity is considered, however, the prevalence of bothersome or significant incontinence (i.e., that which is severe enough to have a significant impact on a person’s quality of life) is between 5 and 10 percent of the community. Initial data suggests that the prevalence is higher in caucasian women; though prevalence in noncaucasian women worldwide requires further study.

There is little information on the proportions of types of urinary incontinence. There are very few incidence studies, and remission may occur either naturally or with treatment. Urinary incontinence is more prevalent during pregnancy and following childbirth, menopause, and hysterectomy. Obesity, lower urinary tract symptoms (e.g., blood in the urine, urine cloudiness, and foul smelling urine or urinary burning), and problems with mobility (functional impairment) or thinking (cognitive impairment) are associated with urinary incontinence. The prevalence of urinary incontinence in men is half that of women and rises more gradually with age. In the United States alone, the economic impact of this condition has been estimated at 18 billion dollars per year, including costs for nursing hours, surgery investigations, pads, and devices for containing incontinence.

Neurological control

The urinary bladder, and the urethral sphincter (a muscular band around the urethra that prevents urine flow) are the two lower urinary tract structures, that together with the supporting muscular pelvic floor, are important for control of urination. Their functions are regulated by coordinated peripheral, autonomic (involuntary), and central (voluntary) nervous system control. The two phases of lower urinary tract function—urine storage and voiding (emptying)—are controlled by urine storage and voiding reflexes. In an infant, during urine storage, the bladder relaxes with filling and the sphincter, under autonomic nervous system control, remains closed. At a certain level of filling, a primitive spinal reflex causes sphincter relaxation and simultaneous bladder (detrusor) contraction, resulting in voiding of urine through the urethra. With maturation of the central nervous system pathways, continence is learned, with inhibition of the primitive spinal reflexes by voluntary control through the frontal cerebral cortex.

Causes of incontinence

The compression of pelvic nerves and the stretching of the pelvic floor during vaginal delivery can result in neuromuscular damage. The function of the urethral sphincter may thus be compromised, contributing to the higher prevalence of stress urinary incontinence (SUI; loss of urine with stress maneuvers such as coughing, laughing, or sneezing) in women who have had many children, compared with women who have had none. Aging and/or diseases that affect the peripheral, autonomic, or central nervous system control of continence, can also result in urinary incontinence. Some older men and women lose cerebral cortical control for unclear reasons, resulting in an unstable, ‘‘overactive’’ bladder (so called idiopathic detrusor instability). This condition is manifested by urinary urgency (e.g., the sudden need to void) and urgency incontinence.

Diseases affecting the cerebral cortex, such as strokes and multiple sclerosis, may result in bladder overactivity (detrusor hyperreflexia) because of central nervous system involvement. Diseases that affect the midbrain or spinal cord, such as multiple sclerosis and spinal cord injury, interfere with the coordination of sphincter relaxation during voiding. This loss of synchronization of sphincter relaxation with bladder contraction is termed detrusor-urethral dyssynergia, and results in voiding that is uncoordinated and incomplete.

Interference of bladder sensory nerves due to long-standing diabetes or physical injury to the pelvic motor nerves may result in loss of bladder sensation or contractility of the detrusor muscle. This causes the bladder to contract poorly, resulting in incomplete emptying of the bladder and urine retention. Obstruction to the flow of urine from the bladder commonly occurs in elderly men due to prostatic gland enlargement. Narrowing of the urethra (urethral stricture ) in men or women can also cause physical obstruction to urine flow, resulting in urinary retention and overflow incontinence. In older men, radical surgery for prostate cancer can interfere with sphincteric urinary control. However, urgency urinary incontinence is the most common type of incontinence in men, with lower urinary tract symptoms, functional and cognitive impairment, prostatectomy and urological conditions as recognized risk factors. This condition can be a symptom of an enlarged prostate.

In developing countries where health care resources are scarce, maternal birth injury due to obstructed labor is not uncommon. Injury to the urethra, bladder, and vagina can result in the formation of fistula, which are abnormal tracts that connect the bladder or urethra directly with the vagina, resulting in constant uncontrolled urine loss. For women affected, this is a devastating complication.

Post-menopausal estrogen decline may cause changes in the urogenital tract, especially shrinkage (atrophy) of supporting tissue. With age, pelvic muscle function is reduced and pelvic tissues lose elasticity. Obesity in older women increases abdominal pressure and may be a contributing factor to SUI.

Assessment

A detailed continence history, bladder diary, physical examination, and measurement of residual urine in the bladder after voiding are components of a continence assessment. Commonly questions are asked about congenital abnormalities, attainment of continence, previous urinary tract infections, obstetric history, neurologic diseases, and previous gynecologic surgery. Some medications have an adverse influence on lower urinary tract function and may promote incontinence. Questions about the quality, type, and timing of fluid intake over a twenty-four hour period; and about smoking, bowel pattern of function, sexual function, and quality of life, can identify reversible lifestyle factors. A one-week bladder diary captures frequency of voiding and wet (incontinent) events. A bladder diary can be repeated after treatment to show objective improvement. If continence pads are used, the number and type are noted. In some instances, measurement of the voided volume is helpful. The loss of urine with stress maneuvers such as coughing, sneezing, or exercise, or loss of urine with urgency may suggest the underlying mechanism of incontinence. Sometimes these symptoms occur together.

In women, the physical examination includes vaginal inspection for signs of post-menopausal estrogen deficiency, pelvic organ prolapse, urogenital fistula, and assessment of voluntary contraction of the muscular pelvic floor. In men, digital rectal examination assesses the size, symmetry, and consistency of the prostate gland, and the examination helps rule out prostate cancer.

Neurologic examination rules out diseases such as stroke, multiple sclerosis, and Parkinson’s disease, and also assesses the nerve and muscular function of the anal sphincter and sacral sensation. Mental state and mobility are also assessed in the elderly. The former will rule out dementia and assess the person’s ability to learn behavioral interventions.

Any urine remaining in the bladder after voiding is usually abnormal and can be measured by passing a catheter in and out through the urethra. Noninvasive assessment can be done by ultrasound examination of the bladder. Further in-depth assessment of the bladder and urethral structure may be indicated using a cystoscope inserted into the bladder through the urethra. The coordinated function of the bladder and urethra may be evaluated by further sophisticated urodynamic tests. These tests are indicated if there is no improvement with conservative behavioral interventions and drug therapy, or if surgery is contemplated.

Management

Attention to lifestyle issues is an essential part of management. A fluid intake of approximately 1,500 mls in twenty-four hours is usually an adequate amount, except in very warm environmental conditions. Excessive caffeine and alcohol intake will promote urine production and may increase urinary frequency. Fluid intake in the evening or at night may contribute to night-time voiding and incontinence. Smoking promotes coughing and is also associated with SUI. Attention to regular bowel function and avoidance of constipation is important.

Behavioral interventions may be effective in reducing or resolving urinary incontinence. These include timed voiding (bladder retraining) and pelvic muscle exercises. Pelvic muscle exercises can strengthen and improve the responsiveness of the pelvic floor and external sphincter. If the pelvic muscles are contracted rapidly during episodes of urinary urgency, the urgency may be suppressed. Biofeedback and electrostimulation are other modalities that have been tried for various types of incontinence with varying success.

Medications that relax or reduce bladder-muscle overactivity are often effective in reducing urinary urgency and urge incontinence. Side effects such as dry mouth or urinary retention may limit their use in some people, however. For overflow incontinence, medications that reduce the sphincter tone may improve bladder emptying. Intermittent catheterization two to three times per day or, rarely, an indwelling catheter, are appropriate options. Surgery in men to relieve prostatic obstruction that doesn’t respond to medication is often indicated. In women, estrogen replacement for symptoms of estrogen deficiency may reduce urinary urgency or frequency. For urogenital prolapse, vaginal support devices (pessaries) can resolve the prolapse, but not necessarily the associated SUI.

Stress urinary incontinence that doesn’t respond to behavioral interventions responds to a variety of injectable bulking agents, such as collagen, or surgical procedures in up to 90 percent of women. Five-year follow-up studies of these procedures show some return of incontinence. For bladder-vaginal fistula, surgery is successful in 50 to 100 percent of women. Containment of incontinence may be improved with specially designed absorbent pads or external catheter devices in men.

Prevention

The First International Conference for the Prevention of Incontinence, held in England in 1997, made a number of recommendations, including providing information to the public on healthy bladder habits, on when and how to seek help on supportive toilet training practices and attitudes by parents (and their effect on successful attainment of continence), as well as simply providing information that incontinence can be treated. Relatives of people with existing incontinence are likely a receptive group to target with information on treatment. For example, by age seven, 10 to 16 percent of boys and 5 to 15 percent of girls have bedtime incontinence (nocturnal enuresis). By age twelve, this prevalence is 5 percent in boys and 2 percent in girls. This benign delay in maturation will usually respond to appropriate advice on eating, drinking, regular daytime voiding, and reducing fluid intake later in the day.

For prenatal women, regular pelvic muscle exercises can improve the strength and function of the pelvic floor and may reduce the likelihood of postpartum stress urinary incontinence. Regulation of bowel function with diet, avoidance of constipation or straining during voiding also reduces the likelihood of stress incontinence or the falling down (prolapse) of the bladder or rectum into the vagina. Factors that contribute to maternal birth injury, such as childbearing in adolescent females (when pelvic growth is incomplete) and a lack of obstetrical services that can provide prompt Cesarean section, are potentially preventable.

In summary, urinary incontinence is a complex symptom that results from a variety of causes, requiring careful assessment of the type of incontinence and of contributing factors. Urinary incontinence will respond to a variety of measures. Generally, lifestyle and behavioral interventions, which are noninvasive, should be tried first. A positive message for those with incontinence who have never received assessment or treatment is that incontinence may be resolved, improved, or better contained in all sufferers.

Michael J. Borrie

See also Constipation; Menopause; Prostate; Sexuality.

BIBLIOGRAPHY

Abrams, P.; Khoury, S.; and Wein, A. Incontinence: Proceedings of 1st International Consultation on Incontinence, June 28–July 1, 1998, Monaco. Plymouth, U.K.: Health Publications Ltd., 1999.

Agency for Health Care Policy and Research. Urinary Incontinence in Adults: Acute and Chronic Management. Clinical Practice Guidelines No. 2, 1996 update, AHCPR publication No. 96-0682. Washington D.C.: U.S. Department of Health and Human Services, Agency for Health Care Policy and Research, 1996.

Canadian Continence Foundation. ‘‘Clinical Practice Guidelines for Adults.’’ Available on the World Wide Web at www.continencefdn.ca

urge incontinence (erj) n. see incontinence.