Fecal incontinence is the inability to control your bowels. When you feel the urge to have a bowel movement, you may not be able to hold it until you can get to a toilet. Or stool may leak from the rectum unexpectedly.

More than 5.5 million Americans have fecal incontinence. It affects people of all ages—children as well as adults. Fecal incontinence is more common in women than in men and more common in older adults than in younger ones. It is not, however, a normal part of aging.

Causes

Fecal incontinence can have several causes:

Constipation
Constipation is one of the most common causes of fecal incontinence. Constipation causes large, hard stools to become lodged in the rectum. Watery stool can then leak out around the hardened stool. Constipation also causes the muscles of the rectum to stretch, which weakens the muscles so they can’t hold stool in the rectum long enough for a person to reach a bathroom.

Muscle Damage

Fecal incontinence can be caused by injury to one or both of the ring-like muscles at the end of the rectum called the anal internal and/or external sphincters. The sphincters keep stool inside. When damaged, the muscles aren’t strong enough to do their job, and stool can leak out. In women, the damage often happens when giving birth. The risk of injury is greatest if the doctor uses forceps to help deliver the baby or does an episiotomy, which is a cut in the vaginal area to prevent it from tearing during birth. Hemorrhoid surgery can damage the sphincters as well.

Nerve Damage
Fecal incontinence can also be caused by damage to the nerves that control the anal sphincters or to the nerves that sense stool in the rectum. If the nerves that control the sphincters are injured, the muscle doesn’t work properly and incontinence can occur. If the sensory nerves are damaged, they don’t sense that stool is in the rectum. You then won’t feel the need to use the bathroom until stool has leaked out. Nerve damage can be caused by childbirth, a long-term habit of straining to pass stool, stroke, and diseases that affect the nerves, such as diabetes and multiple sclerosis.

Loss of Storage Capacity
Normally, the rectum stretches to hold stool until you can get to a bathroom. But rectal surgery, radiation treatment, and inflammatory bowel disease can cause scarring that makes the walls of the rectum stiff and less elastic. The rectum then can’t stretch as much and can’t hold stool, and fecal incontinence results. Inflammatory bowel disease also can make rectal walls very irritated and thereby unable to contain stool.

Diarrhea
Diarrhea, or loose stool, is more difficult to control than solid stool that is formed. Even people who don’t have fecal incontinence can have an accident when they have diarrhea.

Pelvic Floor Dysfunction

Abnormalities of the pelvic floor can lead to fecal incontinence. Examples of some abnormalities are decreased perception of rectal sensation, decreased anal canal pressures, decreased squeeze pressure of the anal canal, impaired anal sensation, a dropping down of the rectum (rectal prolapse), protrusion of the rectum through the vagina (rectocele), and/or generalized weakness and sagging of the pelvic floor. Often the cause of pelvic floor dysfunction is childbirth, and incontinence doesn’t show up until the midforties or later.

Diagnosis

The doctor will ask health-related questions and do a physical exam and possibly other medical tests.

 
• Anal manometry checks the tightness of the anal sphincter and its ability to respond to signals, as well as the sensitivity and function of the rectum.  
• Anorectal ultrasonography evaluates the structure of the anal sphincters.  
• Proctography, also known as defecography, shows how much stool the rectum can hold, how well the rectum holds it, and how well the rectum can evacuate the stool.  
• Proctosigmoidoscopy allows doctors to look inside the rectum for signs of disease or other problems that could cause fecal incontinence, such as inflammation, tumors, or scar tissue.  
• Anal electromyography tests for nerve damage, which is often associated with obstetric injury.

Treatment

Treatment for fecal incontinence depends on the cause and severity; it may include dietary changes, medication, bowel training, or surgery. More than one treatment may be necessary for successful control since continence is a complicated chain of events.

Dietary Changes
Food affects the consistency of stool and how quickly it passes through the digestive system. If your stools are hard to control because they are watery, you may find that eating high fiber foods adds bulk and makes stool easier to control. But people with well-formed stools may find that high fiber foods act as a laxative and contribute to the problem. Other foods that may make the problem worse are drinks containing caffeine, like coffee, tea, and chocolate, which relax the internal anal sphincter muscle.

You can adjust what and how you eat to help manage fecal incontinence.

 
• Keep a food diary. List what you eat, how much you eat, and when you have an incontinent episode. After a few days, you may begin to see a pattern involving certain foods and incontinence. After you identify foods that seem to cause problems, cut back on them and see whether incontinence improves. Foods that typically cause diarrhea, and so should probably be avoided, include
  •   caffeine
  •   cured or smoked meat like sausage, ham, or turkey
  •   spicy foods
  •   alcohol
  •   dairy products like milk, cheese, and ice cream
  •   fruits like apples, peaches, or pears
  •   fatty and greasy foods
  •   sweeteners, like sorbitol, xylitol, mannitol, and fructose, which are found in diet drinks, sugarless gum and candy, chocolate, and fruit juices

   

• Eat smaller meals more frequently. In some people, large meals cause bowel contractions that lead to diarrhea. You can still eat the same amount of food in a day, but space it out by eating several small meals.
   

• Eat and drink at different times. Liquid helps move food through the digestive system. So if you want to slow things down, drink something half an hour before or after meals, but not with the meals.
   

• Eat the right amounts of fiber. For many people, fiber makes stool soft, formed, and easier to control. Fiber is found in fruits, vegetables, and grains. You’ll need to eat 20 to 30 grams of fiber a day, but add it to your diet slowly so your body can adjust. Too much fiber all at once can cause bloating, gas, or even diarrhea. Also, too much insoluble, or undigestible, fiber can contribute to diarrhea. So if you find that eating more fiber makes your diarrhea worse, try cutting back to two servings each of fruits and vegetables and removing skins and seeds from your food.
   

• Eat foods that make stool bulkier. Foods that contain soluble, or digestible, fiber slow the emptying of the bowels. Examples are bananas, rice, tapioca, bread, potatoes, applesauce, cheese, smooth peanut butter, yogurt, pasta, and oatmeal.
   

• Get plenty to drink. You need to drink eight 8-ounce glasses of liquid a day to help prevent dehydration and to keep stool soft and formed. Water is a good choice, but avoid drinks with caffeine, alcohol, milk, or carbonation if you find that they trigger diarrhea.

Over time, diarrhea can rob you of vitamins and minerals. Ask your doctor if you need a vitamin supplement.

Medication
If diarrhea is causing the incontinence, medication may help. Sometimes doctors recommend using bulk laxatives to help people develop a more regular bowel pattern. Or the doctor may prescribe antidiarrheal medicines such as loperamide or diphenoxylate to slow down the bowel and help control the problem.

Bowel Training
Bowel training helps some people relearn how to control their bowels. In some cases, it involves strengthening muscles; in others, it means training the bowels to empty at a specific time of day.

 
• Use biofeedback. Biofeedback is a way to strengthen and coordinate the muscles and has helped some people. Special computer equipment measures muscle contractions as you do exercises—called Kegel exercises—to strengthen the rectum. These exercises work muscles in the pelvic floor, including those involved in controlling stool. Computer feedback about how the muscles are working shows whether you’re doing the exercises correctly and whether the muscles are getting stronger. Whether biofeedback will work for you depends on the cause of your fecal incontinence, how severe the muscle damage is, and your ability to do the exercises.  
• Develop a regular pattern of bowel movements. Some people—particularly those whose fecal incontinence is caused by constipation—achieve bowel control by training themselves to have bowel movements at specific times during the day, such as after every meal. The key to this approach is persistence—it may take a while to develop a regular pattern. Try not to get frustrated or give up if it doesn’t work right away.

Surgery
Surgery may be an option for people whose fecal incontinence is caused by injury to the pelvic floor, anal canal, or anal sphincter. Various procedures can be done, from simple ones like repairing damaged areas, to complex ones like attaching an artificial anal sphincter or replacing anal muscle with muscle from the leg or forearm. People who have severe fecal incontinence that doesn’t respond to other treatments may decide to have a colostomy, which involves removing a portion of the bowel. The remaining part is then either attached to the anus if it still works properly, or to a hole in the abdomen called a stoma, through which stool leaves the body and is collected in a pouch.

Reference:

National Digestive Diseases Information Clearinghouse, USA.