Fecal Incontinence

How bowel control works

Continence depends on several parts working together:

• The rectum stretches to store stool until it is convenient to go.
• Sensory nerves tell you the rectum is filling and whether it contains gas, liquid or solid.
• The internal anal sphincter, an involuntary muscle, keeps the anus closed at rest and provides most resting pressure.
• The external anal sphincter and puborectalis muscle, which you control, squeeze when you need to hold on.
• Stool consistency: formed stool is far easier to hold than liquid.

Problems in any one can usually be compensated for by the others. Incontinence often develops when two or more fail, for example an old childbirth injury combined with new diarrhea.

Types of fecal incontinence

Causes and risk factors

• Childbirth: vaginal delivery can tear or stretch the anal sphincters and the pudendal nerve. Risk is higher with forceps, a first baby, a baby over 4 kg (8.8 lb) and a long pushing stage. Some injuries are recognized at birth, others only years later.
• Chronic diarrhea: from irritable bowel syndrome, inflammatory bowel disease, celiac disease, bile acid malabsorption or medicines.
• Constipation and impaction, especially in older adults and people in care homes.
• Nerve damage: diabetes, multiple sclerosis, spinal cord injury, stroke, dementia, and pudendal nerve injury from chronic straining.
• Anorectal surgery: for hemorrhoids, fistula or fissure.
• Rectal prolapse and hemorrhoids.
• Pelvic radiation for prostate, cervical or rectal cancer.
• Congenital conditions such as anorectal malformations and spina bifida.

Other risk factors are older age, obesity, smoking, physical inactivity and urinary incontinence, which often occurs alongside.

Diagnosis

History and examination

A doctor asks about the type, frequency and severity of leaks, stool consistency, childbirth, surgery and medicines. A scoring tool such as the Wexner (St Mark's) score measures severity and response to treatment. Examination includes looking at the anal skin, a digital rectal exam to feel resting tone and squeeze, and checking for prolapse with straining.

Specialist tests

• Endoanal ultrasound: shows tears or gaps in the internal and external sphincters.
• Anorectal manometry: a thin catheter measures resting and squeeze pressures, rectal sensation and the anorectal reflexes.
• Defecography: X-ray or MRI pictures during evacuation to look for prolapse, rectocele or poor emptying.
• Colonoscopy or flexible sigmoidoscopy: when there is bleeding, a bowel habit change or age-related cancer screening is due.
• Nerve studies in selected cases.

Treatment

Treatment follows a stepped approach.

Step 1: Stool and bowel management

• Soluble fiber (psyllium) to firm stool.
• Loperamide for loose stools, which also increases internal sphincter tone; follow the label dose or your doctor's advice.
• Treating the cause of diarrhea, for example bile acid binders for bile acid diarrhea.
• Laxatives, enemas or suppositories for constipation and overflow, and scheduled toilet visits.

Step 2: Pelvic floor rehabilitation

Biofeedback therapy uses sensors to show you on a screen how your anal muscles are working, so you can learn to squeeze harder and longer and to sense rectal filling earlier. Delivered by a specialist physical therapist or nurse over several sessions, it improves symptoms in the majority of motivated patients. Daily pelvic floor exercises continue at home.

Step 3: Devices and minimally invasive treatment

• Anal plugs or vaginal bowel-control inserts for selected people.
• Transanal irrigation: washing out the lower bowel with water at set times so it stays empty, useful for neurogenic bowel.
• Bulking injections into the anal canal for passive leakage, with modest benefit.

Step 4: Surgery and nerve stimulation

• Sacral nerve stimulation (sacral neuromodulation): a small implanted device stimulates the nerves that control the bowel and pelvic floor. A trial period comes first. It helps many people whose incontinence persists despite conservative treatment, with or without a sphincter defect.
• Sphincteroplasty: overlapping repair of a torn external sphincter, often after childbirth injury. Results tend to fade over years.
• Rectal prolapse repair where prolapse is the cause.
• Colostomy: a last resort that can greatly improve quality of life when other treatments fail.

Living with fecal incontinence

Many people withdraw from work and social life. Practical measures help: knowing where toilets are, carrying a change kit, using absorbent pads designed for bowel leakage, and protecting skin with barrier creams. Continence nurses and specialist physical therapists are valuable sources of support. Fecal incontinence is also linked to anxiety and depression, which deserve treatment in their own right.

For practical first steps if you are experiencing leakage now, see bowel leakage.

Frequently asked questions

What is the best treatment for fecal incontinence?

There is no single best treatment. Most people start with fiber, treating diarrhea or constipation, and pelvic floor biofeedback, which help a majority. Sacral nerve stimulation and surgery are reserved for people who do not improve enough after several months of these measures.

What is the difference between urge and passive fecal incontinence?

Urge incontinence means you feel the need to go but cannot hold on, usually from external sphincter weakness or a stiff rectum. Passive incontinence means stool leaks without you noticing, usually from internal sphincter weakness or reduced sensation.

Can fecal incontinence after childbirth be fixed?

Often, yes. Many women improve with pelvic floor physical therapy and biofeedback in the months after birth. Sphincter tears are usually repaired at delivery. Persistent leakage can be treated with further therapy, sacral nerve stimulation or surgical repair.

Does Kegel exercise help bowel incontinence?

Yes. Regular pelvic floor (Kegel) exercises strengthen the external anal sphincter and puborectalis muscle. They work best when taught by a specialist and combined with biofeedback, so you know you are squeezing the right muscles.

Is fecal incontinence a normal part of aging?

No. It becomes more common with age, but it is not normal and is usually treatable. Constipation with overflow, medicine side effects and weak pelvic floor muscles are common, correctable causes in older adults.