Loss of bowel control, medically known as fecal incontinence, is the involuntary leakage of stool. This symptom can range from occasional, minor leakage to a complete inability to control bowel movements. Understanding its potential causes is important.
Understanding Fecal Incontinence
Fecal incontinence refers to the accidental passage of solid or liquid stool or mucus. It can manifest as an occasional smear or a complete loss of control. Severity varies greatly.
There are two primary forms: urge incontinence and passive incontinence. Urge incontinence involves a sudden, intense need to have a bowel movement where the individual cannot reach a toilet in time. Passive incontinence occurs when stool passes without conscious awareness.
Fecal incontinence is common but often underreported due to embarrassment. Its prevalence ranges from 7% to 15% in the general population, increasing with age. For example, it affects about 2.6% of individuals aged 20-29, rising to 15.3% in those aged 70 and over.
Common Non-Cancerous Causes of Fecal Incontinence
Fecal incontinence can arise from various non-cancerous factors, often disrupting the complex system of bowel control.
Nerve Damage
Nerve damage can impair the ability to sense stool in the rectum or control the anal sphincter muscles. Conditions like diabetes, multiple sclerosis, and spinal cord injuries can lead to neurogenic bowel dysfunction, affecting the coordinated interaction between muscles and nerves in the gastrointestinal tract.
Muscle Damage
Damage to the anal sphincter muscles is another frequent cause. Childbirth, especially with a tear or forceps use, is a common reason. Prior anal surgeries or traumatic injuries can also weaken these muscles and their controlling nerves.
Other Factors
Chronic Constipation: Hard, large stools can stretch and weaken sphincter muscles, allowing watery stool to leak around impacted mass.
Chronic Diarrhea: Loose stools can overwhelm the rectum’s capacity, leading to an uncontrollable urge.
Inflammatory Bowel Diseases (IBD): Conditions like Crohn’s disease and ulcerative colitis cause inflammation and diarrhea.
Irritable Bowel Syndrome (IBS): Can lead to changes in bowel habits, including diarrhea or constipation.
Medications: Certain drugs can affect bowel function.
Hemorrhoids: Can prevent complete sphincter closure.
Age-Related Weakening: Anal muscles can weaken with age.
Fecal Incontinence as a Potential Sign of Cancer
While many causes of fecal incontinence are not cancerous, the symptom can sometimes indicate certain cancers, particularly colorectal and anal cancer. Tumors in or near the colon, rectum, or anus can directly interfere with normal bowel function.
Colorectal cancer can cause fecal incontinence through several mechanisms. A tumor in the colon might create a partial obstruction, causing liquid stool to leak past the blockage. Rectal cancer can involve the internal anal sphincter and surrounding muscles, diminishing their function. Additionally, cancer or its treatments (surgery, chemotherapy, radiation) can damage pelvic structures, nerves, and muscles, affecting bowel control. Radiation therapy, for instance, can injure the rectal lining, leading to inflammation, scarring, frequent bowel movements, urgency, and incontinence.
When to Consult a Healthcare Professional
Consulting a healthcare professional for fecal incontinence is advisable, especially if the symptom is new, persistent, or significantly affects daily life. A doctor can accurately determine the underlying cause.
Seek immediate medical evaluation if fecal incontinence is accompanied by:
Blood in the stool
Unexplained weight loss
Significant changes in bowel habits (frequency or consistency)
Severe abdominal pain
Rectal pain or pressure
Sensation of incomplete bowel emptying
Sudden leg weakness or numbness (may signal nerve damage)
Diagnostic Steps and Treatment Approaches
When evaluating fecal incontinence, healthcare professionals begin with a thorough medical history and a physical examination. The medical history includes questions about leakage frequency and severity, diet, physical activity, and related symptoms. A physical examination involves inspecting the anal area for muscle reflexes and a rectal examination to assess muscle tone and detect abnormalities.
Diagnostic Tests
Further diagnostic tests may be performed to pinpoint the cause:
Anorectal Manometry: Measures anal sphincter muscle strength and coordination with the rectum, and rectal capacity.
Endoanal Ultrasound or MRI: Visualizes anal sphincter muscles and surrounding tissues to identify damage or structural issues.
Endoscopy: Flexible sigmoidoscopy or colonoscopy allows visual inspection of the rectum and colon for inflammation, scar tissue, or tumors.
Anal Electromyography: Assesses nerve damage affecting sphincter function.
Treatment Approaches
Treatment approaches vary depending on the cause and severity.
Conservative Management: Often the first step, including dietary adjustments (e.g., increasing fiber for constipation, adjusting diet to reduce diarrhea) and medications (e.g., anti-diarrheal drugs, bulk-forming laxatives).
Physical Therapy: Pelvic floor exercises strengthen muscles supporting the bowel, rectum, and anus. Biofeedback, using sensors, helps individuals learn to control and strengthen anal muscles.
Surgical Interventions: Considered if conservative measures are insufficient. Options include sphincter repair, sacral nerve stimulation, or in some instances, a colostomy.