If You Don't Ask Her,She Won't Tell You: Fecal Incontinence in Women

Case Report

A44-year-old banking executive came to discuss what she described as a “mortifying problem”: years of uncontrolled passage of flatus and, more recently, fecal incontinence (FI). The first episode of uncontrolled loss of flatus occurred before age 40. Over the past few years, as the flatal incontinence increased in severity and frequency, attempts to cover and excuse herself from work situations to avoid embarrassment were causing extreme stress. One year ago while on her morning walk, she experienced sudden rectal urgency that she interpreted as flatus; however, FI occurred. Despite her hopes to the contrary, this was not a one-time occurrence. She reports daily bowel movements, often more than one per day, that are soft but formed stools. She wears a protective pad daily and often notes fecal staining without awareness of when the seepage occurred. She is otherwise healthy and on no medications. She is gravida 3 para 3, with all normal spontaneous vaginal deliveries. The first two deliveries required episiotomy “without complications” or severe tearing. She has no family history of colon cancer or inflammatory bowel disease (IBS). The review of systems is positive for mild stress urinary incontinence (UI). Physical examination revealed a body mass index (BMI) of 23, no vaginal wall descensus beyond the hymen, and a grade 1–2 rectocele with slightly decreased anal sphincter tone. The next best step in her evaluation would be:

A. Anorectal or endoanal ultrasound

Discussion

Symptomatic pelvic floor disorders affect 32 million women in the United States, with FI occurring in about 13 million. ¹ It is estimated that by the year 2050, 25 million women will be affected by FI. The term, pelvic floor disorders, is used to denote a variety of interrelated clinical entities: UI, FI, pelvic organ prolapse (POP), voiding, and defecatory dysfunction. ² These disorders traditionally have been segregated into anterior (UI, voiding dysfunction), middle (POP), and posterior (FI, defecatory dysfunction) compartments, ³ although clinical presentations are not always confined to a single compartment. FI in and of itself is not a disease state but rather is a symptom of an underlying disorder or disorders. ⁴

FI lacks a consensus definition, but one generally accepted is involuntary loss of liquid or solid stool for more than 1 month ⁵ or more broadly stated to include inadvertent, excessive escape of flatus as well. ⁶ It is a nonfatal illness with minor physical complaints, such as perianal dermatitis, but the emotional consequences for the individual can be severe. In addition to the significant embarrassment and anxiety brought on by the condition, avoidance of social situations can lead to social isolation. ^6,7 The prevalence of FI varies in studies because of differing definitions and reluctance on the part of patients to report the disorder. ⁸ FI in the community has been reported at rates of 2%–26%, whereas nursing homes report FI in 50% of their residents. ⁹ In women, the prevalence of symptomatic FI has been reported at rates of 7%–25%. ^{10 –12}

Risk factors for FI include increasing age, poor physical or mental health, anorectal procedures, diarrhea, and female gender. In women, additional factors include IBS (diarrhea), obesity, UI, rectal urgency, and complicated or operative vaginal births. ^10,13,14 Although there is evolving clear evidence of the relationship between pelvic floor disorders and vaginal delivery, ^15,16 there is no way to determine which women are at greatest risk. Thus, advising cesarean section to prevent later pelvic floor disorders is not recommended. ¹¹

Evaluation of a patient who reports FI should include a detailed incontinence history. Patients should be interviewed about other medical conditions, current medication use, and baseline bowel pattern. Careful questioning about the severity and nature of FI and its effect on quality of life, daily activities, and any evidence of depression should be pursued. ⁶ Physical examination should include a pelvic examination to assess for evidence of POP and inspection of the perineum, with a careful inspection of anus and rectum. The digital rectal examination can rule out fecal impaction or mass as well as assess anal canal tone and contraction of the anal sphincter and puborectalis muscle. ⁷

Further diagnostic studies should be based on the patient's presenting symptoms and physical findings. ^6,7,17 Patients with a complaint of change in stool (diarrhea or constipation) should be worked up accordingly, with laboratory and stool studies to rule out infection or other metabolic disorder, such as thyroid dysfunction. Colonoscopy should be performed if there is evidence of structural or inflammatory abnormality ⁶ or if the patient is >50 years of age without previous colonoscopy. A trial of conservative management in diarrhea-predominant FI, especially in older patients, should also be considered before proceeding with additional workup. ¹⁷

Our patient reported progressive and involuntary loss of flatus and stool without associated symptoms or physical findings to warrant extensive laboratory, stool, or endoscopic studies. At this point, measurement of anal function and structure will help in identifying her specific cause of FI, which will then further guide management decisions. ⁶

Answer: C

Anal manometry (Answer C) with sensory testing is the next best diagnostic test for our patient. Anal manometry measures a variety of factors, including internal anal sphincter resting tone and external anal sphincter squeeze pressures, rectal sensation, and the rectoanal inhibitory reflex. ^6,17 Abnormally low resting pressure suggests an internal anal sphincter defect, whereas low squeeze pressures point to external anal sphincter defects. ¹⁸ Rectal sensory threshold (the first detectable sensation), which can be determined with rectal balloon distention, helps in patient selection for biofeedback. Loss of rectal sensation can be seen in diabetes mellitus, chronic constipation, perineal trauma, neuropathy, and central nervous system disease. FI is prevalent among patient groups with sensory and structural abnormalities of the pelvic floor. Childbirth is one of the major causes of FI in young and middle-age women. The incidence increases after operative vaginal births, grade 3–4 episiotomy, and with increasing parity. ^11,15,16

Imaging studies for patients should be based on the findings at anal manometry. ¹⁷ If demonstrated, low sphincter pressures can be further evaluated with anorectal or endoanal ultrasound or pelvic MRI to assess structural abnormalities, such as anal sphincter injury or fistulas. Therefore, answers A and B are both incorrect as the next best step.

Treatment options for FI include nonoperative interventions, such as bulking agents to improve stool consistency, pelvic floor muscle retraining via biofeedback, antidiarrheal drugs, sacral nerve stimulation, and surgical procedures. ¹⁹ Biofeedback for FI has been shown to be effective ²⁰ ; however, patient selection is an important factor in predicting whether or not a patient may ultimately benefit. ^5,20 Surgery is aimed at correcting a mechanical defect or augmenting a functionally deficient but structurally intact sphincter complex. ¹⁹ For this patient, referral for either biofeedback or to a colorectal surgeon would be premature at this point.