Anal leakage, or fecal incontinence, is the accidental passing of stool from the anus. Anal leakage can range from an occasional leak when passing gas to completely losing control of the bowel.
There are two common types of fecal incontinence:
- Urge incontinence: A person has a strong urge to have a bowel movement, but it occurs so suddenly that they are unable to make it to the toilet in time.
- Passive incontinence: A person has a bowel movement without being aware that they need to pass stool.
People with fecal incontinence may also experience other symptoms, such as:
There are many causes of fecal incontinence. For some people, a combination of problems is responsible for this issue.
Diarrhea causes a person’s rectum to fill up quickly with loose, watery stool. Loose stool is more difficult to keep in the rectum than solid stool, causing or worsening fecal incontinence.
Digestive tract problems may cause diarrhea. These include:
The findings of a Dutch study suggest that constipation and fecal incontinence occur together in 3.5% of the population. Among the study participants, this cooccurrence was significantly more likely in people aged 18–34 years old.
Potential causes of constipation with fecal incontinence include:
- Fecal overflow: When people have severe constipation, a large amount of hard, dry stool becomes stuck in the rectum, which is known as fecal impaction. As the person has trouble passing the impacted stool out of the anus, the bowel starts to leak watery stool around the blockage. This overflow of watery stool might look like diarrhea and soil underwear.
- Pelvic floor weakness: If a person has constipation and strains excessively, their pelvic floor may weaken, which could lead to fecal incontinence.
- Rectum emptying disorders: If someone has a condition that prevents them from completely emptying their rectum, they may experience the leakage of stool after a bowel movement.
The muscles in the pelvic floor, rectum, and anus can become injured or weakened by:
- cancer surgery
- hemorrhoid removal
- surgery for anal abscesses and fistulas
Damage and weakness in these areas may affect the ability of the anus to remain closed, which allows stool to leak out.
If the nerves that control a person’s pelvic floor, rectum, and anus sustain damage, they may no longer work properly. It may become difficult for a person to know when they have stool in the rectum, which can lead to fecal incontinence.
Causes of nerve damage include:
Fecal incontinence is common among people with neurological diseases that affect the nerves that play a role in the function of the pelvic floor, rectum, and anus. These diseases include:
Loss of rectal storage capacity
The rectum normally stretches to store stool. If the rectum becomes inflamed or scarred, it can stiffen, which limits how much it can stretch.
Causes of rectal inflammation and scarring include:
- rectal surgery
- pelvic radiation therapy
When a person has hemorrhoids, the anus is unable to close completely, which causes small amounts of stool to leak out of the opening.
Rectal prolapse is a condition that causes part of a person’s rectum to protrude out of their anus. Fecal incontinence can occur when a rectal prolapse prevents the muscles around the anus from closing.
Rectocele is a condition that occurs when the muscles that separate the vagina and rectum weaken, allowing the rectum to bulge through the vaginal opening.
A person may find it hard to empty their bowels fully because of the rectocele. Small amounts of stool may be retained in a rectocele after a bowel movement and seep out of the anus.
Pregnancy and childbirth
Fecal incontinence may affect up to about 10% of pregnant women and 2–8% of women 3 months after childbirth.
Fecal incontinence may sometimes last longer, with 9–12% of women reporting fecal incontinence 6–12 years after delivery.
Research has suggested that a third- or fourth-degree rupture of the anal sphincter during childbirth is most commonly responsible for postpartum fecal incontinence.
When people are inactive for several hours each day, solid stool may begin to build up in the rectum. Fecal incontinence may occur when liquid stool starts to leak around the solid stool.
The cause of fecal incontinence will determine the method of treatment.
A 2016 study suggests that conservative management, which may involve dietary changes, bowel training, pelvic floor strengthening exercises, and medicines, may result in a 60% improvement in symptoms and stop fecal incontinence in about 1 in 5 people.
Fecal incontinence treatments that a person can try at home include:
- Antidiarrheal drugs: Over-the-counter (OTC) medicines, such as loperamide (Imodium) or bismuth subsalicylate (Pepto-Bismol), can treat fecal incontinence if diarrhea is the cause.
- Bulk laxatives: OTC laxatives, stool softeners, and fiber supplements can relieve fecal incontinence if the cause is constipation. These medicines include methylcellulose (Citrucel) and psyllium (Metamucil).
- Dietary changes: Making dietary changes can relieve or prevent fecal incontinence. A doctor can explain which foods and beverages worsen diarrhea so that a person can avoid them. Eating more fiber and drinking more liquids may alleviate constipation and hemorrhoids.
- Bowel training: A doctor may suggest that a person trains to have a bowel movement at specific times of the day to help them gain greater bowel control.
- Pelvic floor exercises: Tightening and relaxing the muscles in the pelvic floor, rectum, and anus can strengthen them. A 2019 study found that people who followed a supervised pelvic floor muscle training program had higher odds of reporting an improvement in fecal incontinence symptoms than those who did not.
Fecal incontinence treatments that a doctor may recommend include:
- Biofeedback therapy: This treatment uses devices to help people learn how to strengthen and control their pelvic floor area.
- Sacral nerve stimulation: The sacral nerves control the rectum, colon, and anal sphincter. Electrical stimulation of the sacral nerves can help them work properly.
- Prescription medicines: A doctor may prescribe medicine if OTC products are not effective.
- Vaginal balloon: A doctor may recommend a device that inflates a balloon inside the vagina. The inflated balloon puts pressure on the rectal area, which prevents stool from leaking out. A person can add air to the device or remove it to control the passing of stool.
- Nonabsorbable bulking agents: These are substances that a doctor can inject into the wall of the anus to prevent leakage.
- Surgery: A doctor may recommend surgery if all other treatments are unsuccessful or if an injury to the anal sphincter or pelvic floor muscles is causing fecal incontinence.
Anyone who has persistent fecal incontinence should see a doctor.
The doctor can determine the underlying cause and recommend the appropriate treatment.
Anal leakage, better known as fecal incontinence, is a common symptom of many conditions and injuries.
At-home treatments, such as OTC medications, dietary changes, and bowel training, can often improve or stop the symptoms altogether.
If home treatments do not work, a doctor can diagnose and treat the underlying cause of fecal incontinence.