Incontinence of Stool (Accidental Bowel Leakage)

What stool incontinence is

Staying continent depends on several things working together:

• Stool consistency: formed stool is much easier to hold than liquid.
• The rectum: it stretches to store stool and senses when it is full.
• The anal sphincters: an internal ring that works automatically and keeps you closed at rest, and an external ring you squeeze voluntarily.
• The pelvic floor muscles, especially the puborectalis sling.
• Nerves linking all of these to the spinal cord and brain.

Problems with any of these can cause leakage. Often two or more combine, for example mild sphincter weakness that only causes accidents during diarrhea.

Types of fecal incontinence

Causes

Diarrhea

Loose stool is the single biggest trigger. Infections, irritable bowel syndrome, inflammatory bowel disease, lactose intolerance, celiac disease, bile acid diarrhea, laxative overuse, and medicines such as metformin and some antibiotics can all cause urgency and accidents.

Constipation and impaction

Chronic constipation stretches the rectum and weakens sensation. A hard mass of stool can block the rectum while liquid stool from higher up seeps around it. This is common in nursing home residents and people taking opioids, and is often mistaken for diarrhea.

Sphincter and pelvic floor damage

• Childbirth: tears into the anal sphincter during vaginal delivery, especially with forceps, a large baby or a long second stage. Symptoms can appear right away or years later, often after menopause.
• Anal surgery: for fistulas, fissures or hemorrhoids.
• Aging: the sphincter muscles naturally weaken.
• Rectal prolapse and large hemorrhoids, which prevent a tight seal.

Nerve and brain problems

Diabetes, multiple sclerosis, spinal cord injury, stroke, spina bifida, dementia and Parkinson's disease can reduce sensation or control. A sudden onset with leg symptoms may be cauda equina syndrome, a surgical emergency.

Reduced rectal storage

Inflammation (proctitis), radiation therapy to the pelvis, and surgery that removes part of the rectum reduce how much the rectum can hold, causing urgency and frequency.

How doctors assess it

Many people are embarrassed to bring it up, but doctors see it often and it is treatable. A doctor will ask:

• how often accidents happen and whether stool is solid, liquid or gas
• whether you feel the urge first (urge) or not (passive)
• your usual bowel habit, diet, medicines and childbirth history
• about urinary leakage, back problems or neurological symptoms

A physical exam includes looking at the anus, a digital rectal exam to feel sphincter tone and squeeze, and checking for impaction, prolapse or a mass.

Tests may include:

• stool tests and blood tests for causes of diarrhea
• colonoscopy or sigmoidoscopy for persistent diarrhea or bleeding
• anorectal manometry: measures sphincter pressures, sensation and reflexes
• endoanal ultrasound: shows tears in the sphincter muscles
• defecography or MRI for prolapse and pelvic floor problems

Treatment

Change the stool

• Fiber supplements such as psyllium make stool more formed and easier to control. Increase slowly.
• Identify trigger foods: caffeine, alcohol, spicy or fatty food, dairy if lactose intolerant, artificial sweeteners (sorbitol).
• Loperamide for loose stool, starting at a low dose. Follow the label or your doctor's advice.
• Treat constipation and impaction with laxatives, suppositories or enemas, then a regular bowel program.

Strengthen and retrain

• Pelvic floor exercises: squeeze as if stopping gas, hold for a few seconds, relax, and repeat in sets several times a day.
• Biofeedback therapy: a specialist physical therapist uses sensors to help you strengthen and coordinate the muscles and improve rectal sensation. It helps many people.
• Bowel habit training: trying to empty at the same time each day, often 20 to 30 minutes after a meal, using the natural gut reflex.

Devices and products

Anal inserts, vaginal bowel-control devices, absorbent pads designed for bowel leakage, barrier creams to protect the skin, and planning routes with known toilets.

Procedures

• Sacral nerve stimulation: an implanted device that stimulates the nerves controlling the bowel. Effective for many people when other measures fail.
• Injectable bulking agents into the anal canal.
• Sphincter repair (sphincteroplasty) for a defined tear.
• Prolapse repair.
• Colostomy: for severe cases when nothing else works, it can greatly improve quality of life.

Skin care

Frequent leakage irritates the skin. Clean gently with water or a non-alcohol wipe, pat dry, and use a zinc oxide or petroleum barrier cream. Breathable cotton underwear helps.

Frequently asked questions

What causes incontinence of stool?

The most common causes are diarrhea, constipation with overflow leakage, weak or damaged anal sphincter muscles from childbirth or surgery, and nerve damage from diabetes, MS or spinal problems. Often several factors combine. Sudden loss of control with leg symptoms needs emergency care.

Can fecal incontinence be cured?

Many people become fully continent or greatly improve with treatment. Firming the stool with fiber or loperamide, treating constipation, and pelvic floor therapy with biofeedback help most people. Nerve stimulation or surgery helps others when simpler measures are not enough.

Is bowel leakage a sign of cancer?

Rarely. Most bowel leakage is caused by diarrhea, constipation or weak muscles. A rectal tumor can occasionally cause urgency, leakage and bleeding, so new leakage with blood, weight loss or a change in bowel habit should be investigated.

Why do I leak stool after a bowel movement?

Leakage or soiling after going is often due to incomplete emptying, hemorrhoids, a rectocele (a bulge of the rectum into the vagina) or stool trapped in skin folds. Using a footstool, taking your time, fiber and a pelvic floor physical therapist can help.

Who should I see for bowel incontinence?

Start with your primary care doctor. They can examine you, look for treatable causes and start treatment. You may be referred to a gastroenterologist, a colorectal surgeon or a pelvic floor physical therapist for specialized tests and therapy.