Fecal Incontinence in the Elderly

Synopsis

Fecal incontinence can be a challenging and stigmatizing disease with a high prevalence in the elderly population. Despite effective treatment options, most patients do not receive care. Clues in the history and physical exam can assist the provider in establishing the diagnosis, and direct inquiry about the presence of incontinence is key. Bowel disturbances are common triggers for symptoms and represent some of the easiest treatment targets. Here we review the epidemiology and impact of the disease, as well as delineate a diagnostic and treatment approach for primary care physicians to identify elderly patients with suspected fecal incontinence and to provide effective treatment options.

INTRODUCTION

Fecal incontinence (FI) can be a challenging, stigmatizing disease for elderly patients to manage alone. Fortunately, a variety of treatment options exist for patients once the diagnosis is established, with more promising therapies in development. Despite its potentially devastating psychosocial and economic impact, most patients do not receive care for FI. As the population in the United States ages, the prevalence of FI will rise in turn. Healthcare providers must therefore remain vigilant to assess for FI in their aging patients while directing sufferers to appropriate treatment resources. In this article, we will review the epidemiology, risk factors, diagnosis, and management of FI in the elderly population.

EPIDEMIOLOGY AND IMPACT

Definition:

FI is the unintentional passage of solid or liquid stool. It can coexist with diarrhea, constipation as well as urinary incontinence. By Rome IV criteria¹, FI is no longer described as “functional” (as in Rome III criteria)², and there is no distinction as to the presumed etiology in making the diagnosis. For research purposes, FI is now defined as at least two episodes in a four-week period, whereas previous definitions were less stringent.³

Three subtypes have been described:^4,5

Passive incontinence: The unintentional passage of stool or gas without awareness of its occurrence.

Urge incontinence: The discharge of fecal matter despite active attempts to retain contents. These patients may describe constantly being unable to reach the bathroom in time.

Fecal seepage: The unintentional passage of stool that can follow an otherwise normal defecation, often presenting with fecal staining of undergarments. These patients may demonstrate dyssynergia with impaired rectal sensation.

Risk factors:

Several factors drive FI. Anatomic factors involved in maintenance of continence include anorectal sensation, muscle strength, rectal compliance, and neurological integrity.⁶ Anal resting tone is composed 70% of the circular smooth muscle of the internal anal sphincter and 30% of the striated muscle of the external anal sphincter. At rest, the puborectalis component of the levator ani complex helps forms the rectoanal angle to provide an additional barrier to incontinence with resting anal sphincter tone serving as an important barrier to passive incontinence (Figure 1). In healthy individuals, both the puborectalis and the external anal sphincter can be voluntarily contracted to avoid defecation. Aging results in several related neuromuscular changes including reduced anal resting and squeeze pressures, reduced rectal compliance, reduced rectal sensation, and an increased threshold to sense volume^7,8—all physiologic alterations that can predispose to FI.

Figure 1:

Anorectal anatomy relevant to fecal incontinence. (From Rao SS, Bharucha AE, Chiarioni G, et al. Anorectal disorders. Gastroenterology. 2016;150(6):1432; with permission.)

There has been much debate over the role of obstetric injury in the development of FI. Vaginal delivery has been shown to cause anal sphincter injury despite the initial absence of clinical symptoms.⁹ It was therefore previously thought that obstetric injury may be major contributing risk factor in FI in older women.¹⁰ However, more recent data indicate that bowel disturbances such as diarrhea and IBS are the main risk factors for FI in the elderly, rather than obstetric history.¹¹ Such injuries likely remain an important risk factor in immediate post-partum FI,¹² rather than late-onset FI, though obstetric injuries may nevertheless work synergistically with the aforementioned neuromuscular changes to increase risk of FI with aging. In the elderly, recognition of bowel disturbances driving FI can have tremendous therapeutic implications, as they are relatively easier to correct than neuromuscular injuries to the pelvic floor.

Several important medical comorbidities are associated with FI. Among neurological disorders, diabetes mellitus as well as stroke are correlated with FI in older patients,¹³ and FI in patients with multiple sclerosis is common.¹⁴ Within gastrointestinal disorders, FI is more common in inflammatory bowel disease (IBD) patients than non-IBD controls (OR 7.73) in a meta-analysis of seventeen studies and 4671 patients, with a likely multifactorial etiology heightened by local inflammation during a flare.¹⁵ In ulcerative colitis patients who have undergone a curative colectomy with ileal pouch anal anastomosis, FI symptoms are a common complication. 19% of these patients suffer occasional daytime incontinence and 49% suffer nocturnal incontinence at 12 months post-procedure.¹⁶ Other gastrointestinal disorders, including celiac disease and IBS, are also more commonly associated with FI.³³ Among those with preexisting bowel disturbances and predisposing medical conditions and demographics, more aggressive screening for FI is warranted.

Demographic risk factors for FI remain murky. A cross-sectional survey found an increased likelihood of FI in Hispanic and male patients, although these patients may not frequently present for FI care. Alternatively, another study found that white women (not including those identifying as Hispanic) were more likely to develop incident FI compared to black male and female patients.¹⁷ Those seeking care to appear to be predominantly women,^18,19 which may have previously driven the assumption that obstetric injuries were the main risk factor for FI. Nonetheless, the sex split for FI remains controversial, with some arguing for an even distribution among men and women,^18,20,35 and others arguing for a strong female predominance.³²

Furthermore, lifestyle factors such as obesity and smoking^21,22 have been demonstrated as modifiable risk factors for FI. Similarly, higher levels of physical activity have been associated with a 25% risk reduction in new FI.²³ Anal intercourse, in both men and women, increases risk of FI (prevalence odds ratios of 2.8 and 1.5, respectively), although this is an area that has received comparatively little research.²⁴ Dietary factors have been shown to lower risk of development of FI, namely fiber intake. Our group demonstrated a modestly decreased risk of new FI, primarily from liquid stool, with increased long-term fiber intake in older women.²⁵ This finding may in turn reflect an improvement in stool consistency among those with bowel disturbances and FI, with the benefit seen at current guideline-recommended fiber intake levels (25g/day).²⁶

Lastly, of particular relevance to the elderly population, additional risk factors include cognition/neurological disease such as dementia or a compromised ability to communicate, and poor mobility.²⁷ Not surprisingly, patients with limitations in their ability to perform activities of daily living have higher odds of FI than those without (OR 2.54 for mobility, 4.03 for dressing, and 7.37 for toilet use).²⁸ Prompted toileting and fitness training among nursing home residents with these issues have had mixed results.^29,30

Prevalence:

Studies from the 1980–1990s cite FI estimates at 2% of the population (and 10–13% of elderly community residents).^31,32 However, the prevalence of this disease is likely more common than previously appreciated, with a recent large population-based study reporting that 1 in 7 Americans have experienced FI,³³ and a cross-sectional survey finding self-reported FI in 36.2% of respondents.³⁴

Estimates of FI prevalence increase with age, hospitalization, and most with institutionalization. In people over age 50, the incidence of FI has been estimated at 7% per ten years,³⁵ and age is independently associated with FI for both men and women other analyses.³⁶ Among hospitalized patients, the incidence of FI rises to 16% (12% of all patients have FI daily),³⁷ and this is estimated to be as high as 33% among the acutely ill.³⁸ Once institutionalized, nearly half of all residents have FI, according to a recent systemic review on older people in care homes.³⁹

Impact:

Given these estimates, the overall burden of FI is significant. Medical complications of particular concern in the elderly are skin breakdown and pressure ulcers. FI can create excess moisture on the skin and enhances the permeability of irritants including enteric enzymes, increasing the risk of pressure ulcer formation.⁴⁰ In elderly patients, pressure ulcer incidence is independently associated with fecal incontinence within the first 48 hours of hospitalization.⁴¹

Economically, FI plays a major role in the $12 billion adult diaper market, projected to reach a value of $19 billion by 2023 with a growth far surpassing baby diapers.⁴² An American mailbased study that analyzed utilization of medical and nonmedical resources for FI as well as lost productivity found that the average annual total cost for FI is $4,110 per person.⁴³ Finally, patients with FI have more frequent healthcare visits per year than those without (average difference of 4.21 visits/year), and more severe symptoms are associated with increased cost.⁴⁴

Several studies have demonstrated an increased risk for institutionalization among patients with FI.^45,46,47 FI is associated with an increased likelihood of geriatrician referral to a skilled nursing facility, ranking among mobility restrictions, cognitive decline, and multiple chronic illnesses as major factors in the risk for nursing home referral.⁴⁸ Moreover, FI disproportionately increases the burden on caregivers, increasing the likelihood for the institutionalization of a relative.^49,50

Beyond its economic impact, the psychosocial burden of FI cannot be overstated. Major areas of restriction caused by FI include social life, physical activities, hygiene, fear, and embarrassment.⁵¹ Interviews of patients with FI highlight poor self-esteem and feeling that others perceive them as repulsive and impolite.⁵² The perceived shame of FI can lead to increased social isolation and job loss.⁵³ Understandably, FI is linked to increased depression and anxiety as well as decreased quality of life.⁵⁴ An association between FI and likelihood of mortality has even been described in community-dwelling elderly adults, even after adjustment for variables otherwise linked to mortality.⁵⁵

WORKUP OF FECAL INCONTINENCE

History

Asking the patient directly about FI is the most essential, yet frequently underutilized, aspect of the history. Despite its high prevalence, only 10–30% of patients with FI discuss treatment options with their physicians.^56,57 Part of this stems from a lack of systemic screening for FI in the primary care setting.³⁴ Only 13% of patients report being screened by the primary care doctors. Among those who consulted with their doctors about FI, 88% say the discussion was initiated by themselves.⁵⁸ The same study noted that some patients do not consult their doctors about FI because they are unaware that effective treatments exist.

The language providers use to broach a conversation about FI is also important. Physicians can try asking the question using other terms such as “accidental bowel leakage,” which has been shown to be a preferred term by women when discussing FI.⁵⁹ Additionally, providers should take the health literacy of their patients into consideration with these questions as many patients may not have ever heard of FI, or know this is a condition others experience, despite having symptoms themselves.⁶⁰ During the initial history, a physician should probe further if a patient endorses diarrhea, as this may be an intentional mislabeling of FI due to embarrassment.

If FI is suspected, it should be better characterized to elucidate potential underlying, correctable causes. Providers should ask about the onset, frequency, volume, presence of blood, and pattern (gas versus liquid versus solid) of the patient’s FI. Incontinence of urgent liquid stools may suggest the presence of a treatable bowel disturbance such as irritable bowel syndrome (IBS), with symptom improvement possible with conservative measures before referral to specialized care. Passive incontinence of solid stool may suggest more severe neuromuscular dysfunction of the pelvic floor requiring early referral for specialized management. It is also crucial to ask about vision loss, difficulty with communication, and gait impairment, as these factors may point to an overall neurologic or cognitive decline in the elderly.

Next, a thorough medical history should be taken with special attention to diseases that affect that gastrointestinal tract, cognition, and the central or peripheral nervous systems. Dementia, stroke, multiple sclerosis, diabetes mellitus, Parkinson’s disease, IBD, microscopic colitis, and chronic constipation are among the many age-related conditions that can increase risk of FI.

The latter conditions deserve special mention as bowel disturbances are among the most important risk factors for developing FI. Approximately one fourth of patients with IBD experience FI¹⁵, and 10–15% of new IBD cases are diagnosed after the age of 60, despite commonly being seen as a young person’s disease.^61,62 Evidence of anemia, rectal bleeding, and bloody diarrhea as well as an elevated fecal calprotectin or fecal lactoferrin should prompt further evaluation with colonoscopy or flexible sigmoidoscopy.

Microscopic colitis is an important cause of chronic diarrhea in the elderly population with an average age at diagnosis of 66 years and a female predilection.⁶³ Patients with microscopic colitis report new-onset watery diarrhea and the disease is associated with certain drugs (NSAIDs, SSRIs) and autoimmune disorders. Endoscopically, the mucosa typically appears normal, however, the diagnosis of microscopic colitis is based on characteristic pathology.⁶⁴ Therefore it is important to communicate to the gastroenterologist performing the colonoscopy that random colonic biopsies are requested with this condition on the differential.

Fecal impaction due to constipation can be complicated by FI, as seen with an overflow diarrhea. This diagnosis is supported by a history of constipation mixed with diarrhea, abdominal discomfort, and evidence of impaction of rectal exam. While a KUB demonstrating severe fecal loading can help determine the etiology of symptoms, the clinical presentation may be the best predictor of this diagnosis.⁶⁵ Our patients frequently describe several days of constipation followed by a “dam breaking” sensation with hard stools progressing to looser stools over a short time period.

In addition to a thorough surgical and obstetric history, the provider should focus on the patient’s diet and medications. New medications (with special attention to recent antibiotics), herbal supplements, or changes in dosing can provide clues to causes of bowel disturbances. Especially in the elderly, side effects as well as drug-drug interactions of all medications should be considered. With a FI prevalence of 22% in diabetic patients,⁶⁶ providers should give careful attention to dietary and medication changes in this population. Artificial sweeteners such as sorbitol can aggravate diarrhea as can medications such as metformin, with their effects on FI compounded by neuropathy-associated rectal hyposensitivity. Physicians should assess dietary fiber intake and evaluate for possible food triggers causing bowel disturbances such as lactose, fructose, or gluten.

Physical Exam

The physical exam should encompass several aspects including a complete neurological examination to encompass cognition, vision, and mobility. The rectal exam will be reviewed here. It is worth noting that confidence in making a diagnosis with rectal examination is strongly associated with the number of rectal exams performed annually, and that patient refusal rates negatively correlate with the comfort level of the physician.⁶⁷

With the patient on their left side with knees and hips flexed, inspect the perianal region for lesions, including skin tags, ulcers or skin breakdown, hemorrhoids, rashes, fissures, and warts or frank masses. Residual stool is frequently seen surrounding the anal opening in patients with FI. A gaping or patulous anal orifice can suggest a neuromuscular etiology of FI and often indicates internal anal sphincter dysfunction.⁶⁸

Eliciting the “anal wink,” can serve as a helpful (though insensitive) measure of S2-S4 nerve root or pudendal nerve function.^5,69 The examiner gently strokes toward the anus with a finger or cotton swab in all four quadrants to assess for a brisk, involuntary anal contraction. Its absence may be indicative of a potential neuropathic problem.⁷⁰

Rectal prolapse can contribute to FI and can be assessed by asking the patient to bear down—preferably in the standing position to take advantage of gravity. Prolapsed rectal mucosa through the anus appears as a rosette of red tissue with care to note whether only radiating folds (suggestive of milder prolapse) or concentrically circular folds appear (suggestive of larger prolapse involving the entire bowel wall).⁷¹ Having the patient bear down will similarly expose prolapsing internal hemorrhoids that may prevent an adequate seal of the anal canal and lead to seepage.

Inserting a gloved fingertip into the anal canal allows assessment of sphincter tone at rest and when asking the patient to squeeze voluntarily. The former maneuver primarily assesses the function of the internal anal sphincter and the latter the function of the external anal sphincter (under voluntary control). Next the provider should request that the patient try to expel the inserted finger as the provider observes the degree of perineal descent (3 cm or greater is considered abnormal). Lack of coordination between the rectal push and the anal relaxation is suggestive of dyssynergic defecation, which can predispose to incomplete rectal evacuation and subsequent leakage through a weakened anal sphincter.

Further testing

As described, if bowel disturbances are present, stool studies and colonoscopy or flexible sigmoidoscopy should be considered to evaluate for an underlying etiology. A KUB assessing for stool burden can also be valuable when considering overflow incontinence or megarectum. Other more specific tests include anorectal manometry, balloon expulsion testing, and defecography. These can help identify and characterize structural or sensory abnormalities. However, additional testing in FI does not always change management,⁷² and therefore should not delay initial treatment or sub-specialty referral.

MANAGEMENT

There are several effective treatment options for the management of FI and referral to a gastroenterologist or colorectal surgeon (depending on local expertise) is essential to further determine the optimal treatment options for the patient. Conservative treatment, however, should begin immediately at the primary care level. As a rule, correcting bowel disturbances associated with loose stools and liquid stool incontinence is much easier, less invasive—and in many cases more effective—than invasive options targeting the anal sphincter. Dietary modifications such as increased fiber intake or fiber supplementation as well as reducing foods that can prompt loose stools like coffee or fructose can markedly improve FI.⁷³ Loperamide for diarrhea-associated FI⁷⁴ or laxatives for constipation/fecal impaction-associated FI are common first-line treatments,⁷³ with assessment and treatment of the underlying etiology initiated in the primary care office. For example, FI being driven by bile acid malabsorption can often be treated with cholestyramine effectively whereas FI resulting from an inability to reach the toilet in a Parkinson’s patient can be reduced by ordering a bedside commode. Table 1 lists etiologies of common bowel disturbances, the diagnostic workup, and first-line treatments.

Table 1.

Common bowel disturbances, work-up, and first-line treatments.

Bowel disturbance	Diagnostic work-up	First-line treatment
Irritable bowel syndrome with diarrhea (IBS-D)	History (suggestive features include absence of red flag symptoms, association with defecation), negative infectious and inflammatory work-up	Fiber supplementation, loperamide, antispasmodics (caution in elderly)
Bile acid diarrhea	History (suggestive features include history of cholecystectomy or suspicion of IBS-D)	Cholestyramine, colesevelam, colestipol (caution about spacing out from other medications)
Microscopic colitis	Pathology from endoscopic biopsies	Frequently directed by GI: Budesonide (9 mg daily), smoking and NSAID cessation (may contribute to disease)
Chronic infectious diarrhea	History (suggestive features include recent travel or immunocompromise), fecal giardia/stool ova and parasites/stool culture, fecal leukocyte	Targeted anti-microbial therapy
Inflammatory Bowel Disease	Fecal calprotectin, endoscopy, iron studies	Treatment directed by GI
Lactose intolerance	Dietary history, note that prevalence increases with age	Lactose-free diet, lactase enzyme supplementation
Celiac disease	Dietary history, IgA/tissue transglutaminase	Gluten-free diet
Small bowel bacterial overgrowth	Breath testing, though significant accuracy issues	Antibiotics (preference for nonabsorbable agents, i.e. rifaximin)
Constipation with overflow incontinence	History, KUB	Laxatives, pelvic floor biofeedback

The current anorectum-specific treatments with the best evidence to date are sacral nerve stimulation (SNS), a type of neuromodulation involving outpatient surgical implantation of electrodes adjacent to the sacral nerves,⁷⁵ and biofeedback, which is performed with the assistance of a therapist to retrain a patient’s neuromuscular coordination and improve rectal sensation.^76,77 These treatment modalities have been reviewed in depth,⁷⁸ and typically require subspecialty guidance. In all cases, treatment success is generally defined as ≥50% reduction in weekly FI episodes.⁷⁹

It must be noted that in women with normal stool consistency, loperamide was recently shown to be no more effective than placebo or than an educational pamphlet on FI.⁸⁰ The same randomized control trial did not show a significant difference between biofeedback and an educational pamphlet in this population. This lack of improvement with some of the long-used, traditional interventions in FI with normal stool consistency suggests a patient population with more severe damage to the continence mechanism warranting earlier subspecialty evaluation.

Nonetheless, conservative management by the primary care physician plays an integral role in FI, yielding 60% improvement in symptoms and continence in 20% of patients.⁸¹ It is therefore insufficient to merely make a diagnosis of FI. Rather, it is paramount that a plan is implemented to address it with our suggested algorithmic approach (Figure 2), expediently involving specialists if needed.

Figure 2:

Suggested treatment algorithm for the evaluation of fecal incontinence in the elderly

CONCLUSION

In summary, FI is a widespread issue amongst the elderly with a significant toll on patients and society. With a purposeful history and physical exam, physicians can make the diagnosis and start effective FI treatments, which can be life-changing. While we still have much to learn about the pathophysiology of FI, several exciting new therapies are on the horizon.

Our institution is currently collaborating in a randomized clinical trial for translumbosacral neuromodulation therapy for FI. Translumbosacral neuromodulation therapy is a novel technique that delivers magnetic energy to the lumbosacral nerves, which, unlike sacral nerve stimulation, is non-invasive. As with other options for FI, it remains to be seen if a sham-control clinical trial will demonstrate long-term efficacy.

A number of promising preclinical and observational studies have investigated local injections to the anal sphincter of muscle-derived or mesenchymal stem cells.⁸² A recent phase II, randomized clinical trial using autologous myoblasts demonstrated sustained improvement in FI severity at 12 months.⁸³

Despite these strides, stigma reduction remains an enormous barrier in FI. On an individual provider level, however, the first step in the right direction is as simple as asking the patient.

Key Points:

• Fecal incontinence can be a challenging and stigmatizing disease with a high prevalence in the elderly population

• Despite effective treatment options, most patients with fecal incontinence are never asked by providers about the condition and do not receive care

• Clues in the history and physical exam can assist the provider in establishing a diagnosis for fecal incontinence

• Treating underlying bowel disturbances are one of the most effective first-line treatments for fecal incontinence