Bowel control problems affect at least 1 million people in the United States. Loss of normal control of the bowels is known as fecal (or anal) incontinence. This leads to leakage of solid or liquid stool or gas. Many women are not comfortable talking about bowel control problems. A urogynecologist, a physician trained in treating pelvic floor disorders, can offer help if you are experiencing fecal incontinence or chronic constipation.

Fecal Incontinence

Incidence
Anal incontinence occurs when a woman is not able to control her bowel movements, resulting in accidental passing of stool. This problem affects an estimated 7% of women. Anal incontinence is more common with vaginal delivery than cesarean section because of the potential for damage to the anorectum during vaginal delivery. However, anal incontinence is more common following childbirth of any form, including cesarean section.

Risk Factors
Risk factors include childbirth, vaginal delivery, the use of forceps during to assist vaginal delivery, episiotomy or natural tearing of the tissues during vaginal delivery, aging, neurological conditions, and chronic constipation.

Anal incontinence can occur for several reasons:

• Abnormal stool consistency – Bowel movements with normal formed consistency are easiest to control. Diarrhea or loose bowel movements are more likely to cause anal incontinence because of both looser consistency and increased urgency. Severe constipation can also sometimes lead to anal incontinence.
• Anal sphincter injury -- The circular muscles of the anus that allow us to control bowel movements are called the “anal sphincter muscles”. These muscles can be damaged or torn during vaginal delivery. It is estimated that as many as 40% of women experience muscle injuries in this area during childbirth, more commonly when episiotomy or forceps delivery is performed. Injury to the muscles can cause decreased strength resulting in problems postponing passage of bowel movements. In some cases, the muscle damage can be repaired with surgery.
• Nerve injury – Injury to the anal sphincter nerves can cause decreased sensation and muscle strength, both of which can contribute to anal incontinence. Nerve damage can be caused by injury during vaginal delivery, chronic constipation, or by illnesses that affect the nerves such as diabetes, spinal cord injury, etc. The nerve damage that occurs during vaginal delivery can often improve with healing of the nerves over the next 1 to 2 years after childbirth.
• Prolapse – Rectoceles and other forms of prolapse can sometimes cause anal incontinence by causing stool to be incompletely emptied during bowel movements.
• Fistula – Abnormal tracts known as “fistulas” can rarely develop between the rectum and vagina, following vaginal delivery or vaginal surgery. They can also occur spontaneously as a result of diverticulitis or other bowel conditions.

Evaluation Tools
A specialist such as a urogynecologist, colorectal surgeon, or gastroenterologist should generally evaluate anal incontinence. The evaluation should always begin with discussion of the symptoms and physical examination. Other tests that are sometimes necessary include:

• Ultrasound – to evaluate the anal sphincter muscles
• MRI or defecography – to evaluate the surrounding tissues for possible anatomic problems such as pelvic organ prolapse
• Nerve testing and/or anal manometry – to evaluate possible injury to the nerves which can cause decreased strength and sensation
• Colonoscopy or sigmoidoscopy – to evaluate for other possible causes such as fistula, colitis, Crohn’s disease, etc.

Constipation

Incidence
Constipation is very common, affecting about 1 in 3 women. Constipation can cause several problems including infrequent bowel movements, hard bowel movements, and the need to strain during bowel movements. Sometimes with certain types of constipation, women will need to press on the perineum (the area between the vagina and the anus) or on the back vaginal wall to help pass the bowel movement.

Constipation can occur for several reasons:

• Dietary problems – The most common reason for constipation is not having enough fiber in your diet. Some foods, especially foods high in starch such as white rice, pasta, or white bread are more likely to lead to constipation. It is important to drink enough fluids to keep the stools soft. When there is not enough fiber or water in your diet, the bowel movements are more likely to be hard or irregular.
• Pelvic floor disorders – Rectoceles and other forms of prolapse can sometimes lead to problems with bowel movements. Women who are unable to relax the pelvic floor muscles can also have problems passing bowel movements. This type of problem is more likely to cause problems moving the bowels than problems with irregularity or hard bowel movements. In turn, chronic constipation can cause pelvic floor disorders.
• Medical conditions – Constipation can also occur as a result of abnormal nerve function, usually causing severe irregularity. This can occur by itself or from certain medical conditions such as irritable bowel, thyroid disorders, or neurological conditions such as diabetes or spinal cord injuries, etc. that affect the function of the nerves in the intestines. These types of conditions usually will cause irregularity or hard stools. Many medications lead to constipation as a side effect.
• Intestinal blockage – Rarely, constipation can be caused by blockage from colon cancer, other tumors, or scar tissue from prior infections or surgeries. In this case, the constipation usually continues to get worse until the problem is treated.

Evaluation
Your primary care doctor, OB-GYN, urogynecologist, gastroenterologist, or colorectal surgeon can evaluate constipation. The evaluation should always begin with discussion of the symptoms and physical examination. Other tests that are sometimes necessary include:

• Colonoscopy – Colonoscopy is a procedure done with anesthesia using a scope to examine the colon. This is done to investigate possible blockage of the intestines from cancer or other masses. All women over age 50 should undergo regular colon cancer screening. The best form of colon cancer screening, particularly in women, is colonoscopy. This is recommended beginning at age 50, and then every ten years if the results are normal, more often if polyps are discovered. Other forms of colon cancer screening include sigmoidoscopy, barium enema, and testing of the stool for blood.
• Barium enema – This is an x-ray study that can be used to look for masses that block the intestines.
• CT scan – This is an x-ray study that can be used to look at the intestines or surrounding tissues for causes of constipation such as masses within or around the intestines.
• Nerve testing – These studies are sometimes done to test the nerves in the rectum to check for abnormal sensation that can cause constipation.
• Anal Manometry – This is done to check for normal or abnormal relaxation of the pelvic floor muscles.

Sources
American Urogynecologic Society
Original publication date: May, 2008; Content updated: March, 2012