Fecal incontinence: New therapies, age-old problem

Rigid or flexible proctoscopy may be indicated to rule out inflammatory bowel disease, radiation proctitis, and rectal neoplasm, depending on the patient’s history.

A few diagnostic adjuncts can help
Several adjuncts to physical examination can provide more detailed information about the patient’s condition and facilitate the development of an individualized treatment plan. For example, if rectal prolapse, rectocele with delayed emptying, or enterocele is suspected, consider defecography. If voiding dysfunction coexists with the fecal incontinence, urodynamic testing and cystoscopy may be indicated.

We routinely perform physiology testing and endoanal ultrasound if surgery is planned to address the fecal incontinence, although routine use of these adjuncts is controversial. Because many patients can be managed with conservative medical measures, we do not find it necessary to perform these tests at the time of the first visit.

Anal physiology testing includes manometry (a measure of both resting and squeeze tone) and pudendal nerve terminal motor latency testing.

Manometry can help quantify the severity of muscle weakness and determine the presence or absence of normal anal reflexes. Pudendal nerve testing assesses the innervation of the anal sphincter. There is some evidence that patients who have a pudendal neuropathy have a poor outcome with sphincteroplasty,⁵ although that evidence is controversial. The findings from physiology studies have not been correlated with outcomes of newer treatments, such as sacral neuromodulation (InterStim, Medtronic, Minneapolis, Minnesota). Each physiology lab uses different equipment, so “normal” values vary between institutions.

Endoanal ultrasound is easily performed in an office setting. It is well tolerated and provides anatomic detail of the sphincter musculature. We use a 13-MHz rotating probe to provide 3D imaging of the anal canal. The internal sphincter is represented by a hypoechoic circle surrounded by the hyperechoic external sphincter (FIGURE 1).

In the hands of an experienced examiner, the sensitivity and specificity of endoanal ultrasound in detecting sphincter defects approaches 100%.^6,7 Ultrasound also enables measurement of the perineal body. A normal perineal body measures 10 to 15 mm.

For treatment, try conservative measures first
Bulking agents (fiber), constipating agents (loperamide, etc.), or a laxative regimen with scheduled disimpactions (in patients who have pelvic outlet constipation and overflow incontinence) often can control the symptoms of fecal incontinence, making further interventions unnecessary.

Biofeedback is another option. It uses visual, auditory, and sensory information to train patients to better control anal sphincter muscle function.

A recent randomized study found manometric biofeedback to be superior to simple Kegel exercises in improving fecal continence.⁸ In this study, 76% of patients in the biofeedback group experienced symptom improvement, compared with 41% of patients in the pelvic floor exercise group (P <.001). The long-term benefits of biofeedback are less clear, and patients often need to be reminded to perform their exercises at home and to attend occasional refresher-training sessions. Nevertheless, biofeedback is an important noninvasive option for patients in whom medical management has failed.

Minimally invasive options are now available
Over the past 2 years, minimally invasive treatments for fecal incontinence have emerged, including an implantable sacral neuromodulation device (InterStim) and an injectable dextranomer (Solesta; Salix Pharmaceuticals, Raleigh, North Carolina). Previously, the only surgical option for fecal incontinence was a sphincter repair if a defect was present. The new options may help patients improve their quality of life without having to undergo major surgery.

No one has directly compared the outcomes of these procedures when they are performed by a colorectal surgeon versus a physician of another specialty. It is our belief that the treating physician should have a strong interest in caring for these complex patients and a good working knowledge of the various treatment options.

Related Article Obstetric anal sphincter injury: 7 critical questions about care Ranee Thakar, MD, MRCOG (February 2008)

Sacral neuromodulation
This technique initially was developed for the treatment of overactive bladder and nonobstructive urinary retention and has been used in the United States for the past 15 years for these indications. Improvement in fecal continence was observed in these patients, prompting further studies of its efficacy. In 2011, it was approved by the US Food and Drug Administration (FDA) for the treatment of fecal incontinence. It has since revolutionized the treatment of this disorder, offering a minimally invasive and highly successful alternative to sphincteroplasty.

The InterStim procedure is the only therapeutic modality to include a test phase. The outpatient procedure involves sterile placement of an electrode through the S3 foramen to stimulate the S3 nerve root using fluoroscopic guidance (FIGURES 2 and 3). Patients who experience at least 50% improvement in symptoms are then offered placement of a permanent stimulator.