Do Sphincter Muscles Weaken with Age?

According to the Cleveland Clinic, fecal incontinence is more common in adults over 65, and age is a significant risk factor, but it is not a 'natural' or unavoidable consequence of getting older. Here's a closer look at the question: Do sphincter muscles weaken with age?

Quick Summary

Yes, sphincter muscles can weaken as a natural part of the aging process, which, along with other age-related factors like nerve changes and loss of elasticity, can contribute to incontinence. This weakness is not inevitable and can often be managed through various strategies.

Key Points

• Normal Ageing: Ageing can lead to a natural weakening of the anal sphincter, but it is not an inevitable part of the process, and many factors influence the degree of weakness.

• Multi-Factorial Causes: Weakness is often compounded by other age-related changes, including nerve degeneration, loss of tissue elasticity, and general muscle atrophy.

• Manageable Risk Factors: Lifestyle factors like chronic constipation, obesity, and childbirth trauma can accelerate or worsen sphincter weakness, but many are manageable through lifestyle adjustments.

• Anal Sphincter Composition: The two parts of the anal sphincter, the internal and external muscles, weaken differently with age; the external sphincter can be strengthened with exercise.

• Proactive Management: Pelvic floor exercises (Kegels), a high-fiber diet, proper hydration, and avoiding straining are effective strategies for maintaining and improving continence.

• Seeking Professional Help: If conservative measures don't help, consulting a doctor or a pelvic floor specialist is important for further diagnosis and treatment options like biofeedback or other therapies.

Understanding the Sphincter Muscles

Sphincter muscles are circular muscles that control the passage of substances through openings in the body. While people often think of the anal sphincter, others exist throughout the body, including the lower esophageal sphincter (LES) and the urinary sphincter. The anal sphincter consists of two parts: the internal anal sphincter (IAS), an involuntary smooth muscle that maintains resting tone, and the external anal sphincter (EAS), a voluntary skeletal muscle. The weakening of these muscles, often coupled with other physiological changes, can lead to conditions like fecal or urinary incontinence.

Age-Related Changes in Sphincter Muscles

The aging process affects all parts of the body, and the muscles that maintain continence are no exception. Research indicates that age-related neuromuscular changes can lead to functional decline in the sphincters, but this does not happen to everyone. Several factors contribute to this decline:

• Muscle Atrophy: Sarcopenia, the age-related loss of muscle mass and strength, affects the EAS, which is a voluntary skeletal muscle. Studies have shown a significant decrease in the motor unit firing rates and a compensatory increase in the size of the motor units in the EAS of older adults, indicating a neuromuscular impairment.
• Loss of Elasticity: The IAS, a smooth muscle, can lose some of its elasticity over time. This makes it less effective at maintaining its resting tone, a key component of passive continence. One study noted that aging was associated with IAS thickening in women, but a decrease in resting tone was also found.
• Nerve Degeneration: The nerves supplying the sphincter muscles can also deteriorate with age. This can result in reduced sensation, making it harder for individuals to recognize the need for a bowel movement. This nerve damage, or neuropathy, can be exacerbated by conditions common in older adults, such as diabetes.
• Pelvic Floor Loosening: The entire pelvic floor structure, which supports the sphincter muscles, can weaken and loosen with age, especially in women who have given birth. This loss of support can compound the effects of sphincter muscle weakening.

Factors that Worsen Sphincter Weakness

While some changes are natural, certain lifestyle choices and health issues can significantly worsen sphincter weakness. Fortunately, many of these are modifiable:

• Chronic Constipation and Straining: Repeated straining during bowel movements, often due to chronic constipation, puts excessive pressure on the anal sphincter and pelvic floor muscles. This can lead to muscle and nerve damage over time.
• Obesity: Excess body weight puts additional strain on the pelvic floor and sphincter muscles. Losing weight can help alleviate this pressure and improve symptoms of incontinence.
• Certain Medical Conditions: Neurological disorders such as multiple sclerosis or stroke, and metabolic diseases like diabetes can lead to nerve damage that affects sphincter function.
• Childbirth: Vaginal delivery, particularly with forceps or other trauma, can stretch or tear the anal sphincter muscles, increasing the risk of weakness later in life.
• Hormonal Changes: In women, hormonal changes associated with menopause can contribute to a loss of muscle mass and elasticity in the pelvic region.
• Medications: Some medications can affect bowel movements, either by causing diarrhea or by relaxing the sphincter muscles.

Comparison of Incontinence-Related Conditions

Feature	Age-Related Incontinence	Incontinence from Injury/Trauma
Onset	Gradual, subtle worsening over time.	Often sudden, following an event like childbirth or surgery.
Underlying Cause	Cumulative effects of muscle weakness, nerve degeneration, and tissue elasticity loss.	Direct physical damage to the sphincter muscles or nerves.
Primary Contributing Factors	Sarcopenia, chronic constipation, systemic diseases.	Vaginal childbirth, rectal surgery, severe injury.
Symptoms	Often characterized by a slow leakage or urgency.	Can involve more significant, immediate loss of control.
Effect on Muscles	Generalized muscle weakening and nerve signal impairment.	Localized damage, potentially involving tears or scarring.
Treatment Focus	Management through lifestyle, diet, and muscle strengthening.	Potentially involves surgical repair in addition to conservative methods.

Managing and Strengthening Sphincter Muscles

Although age-related changes are a factor, there are many proactive steps individuals can take to maintain or improve sphincter muscle strength and overall continence:

1. Pelvic Floor Exercises (Kegels): These exercises focus on strengthening the pelvic floor muscles, which provide essential support to the sphincters. Regular practice can improve muscle tone and control, helping to manage incontinence.
2. Fiber-Rich Diet: Eating a diet high in fiber helps prevent constipation and the need for straining. This reduces the pressure placed on the sphincter muscles during bowel movements. Examples of high-fiber foods include legumes, fruits, and whole grains.
3. Hydration: Proper hydration is crucial for preventing constipation. Drinking plenty of water helps keep stools soft and easier to pass.
4. Avoid Straining: When on the toilet, avoid pushing or straining. Allowing the body's natural processes to take over reduces stress on the pelvic floor.
5. Maintain a Healthy Weight: Reducing excess weight can significantly decrease the load on the pelvic floor and improve continence.
6. Biofeedback Therapy: This therapy uses electronic devices to provide real-time feedback on muscle activity. It can help people learn to identify and strengthen their pelvic floor muscles more effectively.
7. Consult a Professional: If symptoms persist, a gastroenterologist or a pelvic floor physical therapist can offer specialized advice and treatment options.

Conclusion

The simple answer to "Do sphincter muscles weaken with age?" is yes, it is a risk factor, but it is far from a universal or inevitable outcome. The overall health of an individual, including their diet, exercise habits, and management of chronic health conditions, plays a significant role. By understanding the causes of weakening and adopting proactive strategies like pelvic floor exercises and a fiber-rich diet, older adults can take meaningful steps to maintain muscle function and control over continence. This empowers individuals to age with greater dignity and confidence.

For more information on digestive health and aging, the National Institute on Aging provides valuable resources.

Frequently Asked Questions

Are weak sphincter muscles a normal part of aging?

While it's more common in older adults, sphincter muscle weakness is not considered an inevitable part of aging. It's often the result of a combination of factors, some of which are treatable or preventable.

What are the common signs of weakening sphincter muscles?

Common signs include fecal incontinence (bowel leakage), gas leakage, urgency to have a bowel movement, and difficulty with bowel control. The severity can range from minor to more significant.

Can Kegel exercises help strengthen sphincter muscles?

Yes, Kegel exercises are a common and effective method for strengthening the pelvic floor muscles, which provide essential support to the sphincter muscles. Regular and correct practice can improve continence.

How does chronic constipation contribute to weakened sphincter muscles?

Chronic straining to pass stool puts excessive and repetitive pressure on the anal sphincter and surrounding pelvic floor muscles. Over time, this can lead to muscle and nerve damage, worsening weakness.

What is the difference between the internal and external anal sphincters?

The internal anal sphincter is an involuntary smooth muscle that maintains resting tone, while the external anal sphincter is a voluntary skeletal muscle that can be consciously squeezed. With age, the IAS loses elasticity while the EAS can lose strength, a key difference for treatment.

Are there other medical conditions associated with weak sphincter muscles?

Yes, several conditions can impact sphincter function, including nerve damage from diabetes or stroke, multiple sclerosis, inflammatory bowel disease, and childbirth trauma.

When should I see a doctor about sphincter muscle weakness?

You should see a doctor if you experience any form of incontinence or difficulty with bowel control. Early diagnosis can help identify underlying causes and lead to more effective management and treatment.