Fecal incontinence

Fecal incontinence (FI), or in some forms, encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents—including flatus (gas), liquid stool elements and mucus, or solid feces. FI is a sign or a symptom, not a diagnosis. Incontinence can result from different causes and might occur with either constipation or diarrhea. Continence is maintained by several interrelated factors, including the anal sampling mechanism, and incontinence usually results from a deficiency of multiple mechanisms. The most common causes are thought to be immediate or delayed damage from childbirth, complications from prior anorectal surgery (especially involving the anal sphincters or hemorrhoidal vascular cushions), altered bowel habits (e.g., caused by irritable bowel syndrome, Crohn's disease, ulcerative colitis, food intolerance, or constipation with overflow incontinence).

Fecal incontinence has three main consequences: local reactions of the perianal skin and urinary tract, including maceration (softening and whitening of the skin due to continuous moisture), urinary tract infections, or decubitus ulcers (pressure sores); People may be too embarrassed to seek medical help and attempt to self-manage the symptom in secrecy from others.

FI is one of the most psychologically and socially debilitating conditions in an otherwise healthy individual and is generally treatable. Management may be achieved through an individualized mix of dietary, pharmacologic, and surgical measures. Health care professionals are often poorly informed about treatment options, Deficits of individual functional components of the continence mechanism can be partially compensated for a certain period, until the compensating components themselves fail. For example, obstetric injury may precede onset by decades, but postmenopausal changes in the tissue strength reduce in turn the competence of the compensatory mechanisms. Diabetes mellitus is also known to be a cause, but the mechanism of this relationship is not well understood.

Childbirth

Vaginal delivery causes stretching of the pelvic muscles and the pudendal nerve. Obstetric injury is a leading cause of fecal incontinence. Obstetric injury may tear the anal sphincters, and some of these injuries may be occult (undetected). The risk of injury is greatest when labor has been especially difficult or prolonged, when forceps are used, with higher birth weights, or when a midline episiotomy is performed. Only when there is post-operative investigation of FI such as endoanal ultrasound is the injury discovered. The nerve is especially vulnerable to stretch damage during childbirth because of the course of the nerve, as it runs in close proximity to pelvic muscles (piriformis and coccygeus) and ligaments, before exiting and then re-entering the pelvic cavity. The damage is likely to occur at the exit from the pudendal canal, because the course of the nerve is relatively fixed at this point. Stretching occurs during delivery, especially from the child's head. 60% of females who sustained obstetric tears were demonstrated to also have pudendal nerve damage. Any damage to the pudendal nerve occurring during childbirth may not become fully apparent until years later, for example at the onset of menopause.

Anal sphincter weakness

The anal canal presents the final barrier to continence. The resting tone of the anal canal is not the only important factor; both the length of the high-pressure zone and its radial translation of force are required for continence. This means that even with normal anal canal pressure, focal defects such as the keyhole deformity can be the cause of substantial symptoms. External anal sphincter (EAS) dysfunction is associated with impaired voluntary control, whereas internal anal sphincter (IAS) dysfunction is associated with impaired fine-tuning of fecal control. The external anal sphincter is supplied by the pudendal nerve. Damage to the nerve supply of the external anal sphincter on one side may not result in severe symptoms because there is substantial overlap in innervation by the nerves on the other side. Disruption of the function of the internal anal sphincter results in reduced resting pressure in the anal canal. This is associated with passive leakage.

Obstructed defecation (incomplete evacuation of stool)

Normal evacuation of rectal contents is 90100%. Obstructed defecation is often due to anismus (paradoxical contraction or relaxation failure of the puborectalis). Rectal storage capacity (i.e. rectal volume + rectal compliance) may be affected in the following ways. Surgery involving the rectum (e.g. lower anterior resection, often performed for colorectal cancer), radiotherapy directed at the rectum, and inflammatory bowel disease can cause scarring, which may result in the walls of the rectum becoming stiff and inelastic, reducing compliance. Reduced rectal storage capacity may lead to urge incontinence, Pudendal neuropathy is one cause of rectal hyposensitivity and may lead to fecal loading or impaction, megarectum and overflow FI (see overflow incontinence).

Overflow incontinence

This may occur when there is a large mass of feces in the rectum (fecal loading), which may become hardened (fecal impaction). Liquid stool elements can pass around the obstruction, leading to incontinence. Megarectum (enlarged rectal volume) and rectal hyposensitivity are associated with overflow incontinence. Hospitalized patients and care home residents may develop FI via this mechanism,

{| class="wikitable" style="float: right; width:400px;"

|+ Drugs that may exacerbate FI and diarrhea

! Drug or mechanism of action !! Common examples

| Drugs altering sphincter tone ||

Nitrates, calcium channel antagonists, beta-adrenoceptor antagonists (beta-blockers), sildenafil, selective serotonin reuptake inhibitors

| Broad-spectrum antibiotics ||

Cephalosporins, penicillins, macrolides

| Topical drugs applied to the anus (reducing pressure) ||

Glyceryl trinitrate ointment, diltiazem gel, bethanechol cream, botulinum toxin A injection

| Drugs causing profuse diarrhea ||

Laxatives, metformin, orlistat, selective serotonin reuptake inhibitors, magnesium-containing antacids, digoxin

| Constipating drugs ||

Loperamide, opioids, tricyclic antidepressants, aluminium-containing antacids, codeine

| Tranquilisers or hypnotics (reducing alertness) ||

Benzodiazepines, tricyclic antidepressants, selective serotonin reuptake inhibitors, anti-psychotics

Central nervous system

Continence requires conscious and subconscious networking of information from and to the anorectum. Defects or brain damage may affect the central nervous system focally (e.g. stroke, tumor, spinal cord lesions, trauma, multiple sclerosis) or diffusely (e.g. dementia, multiple sclerosis, infection, Parkinson's disease or drug-induced). FI (and urinary incontinence) may also occur during epileptic seizures. Dural ectasia is an example of a spinal cord lesion that may affect continence.

Diarrhea

Liquid stool is more difficult to control than formed, solid stool. Hence, FI can be exacerbated by diarrhea. Orlistat is an anti-obesity (weight loss) drug that blocks the absorption of fats. This may give side effects of FI, diarrhea, and steatorrhea.

Radiation

Irradiation may occur during radiotherapy, e.g. for prostate cancer. Radiation-induced FI may involve the anal canal as well as the rectum, when proctitis, anal fistula formation, and diminished function of internal and external sphincter occur. Most people casually engaging in anal sex do not experience subsequent fecal incontinence. However, some practices are more strongly associated with incontinence; including anal fisting, high frequency of anal sex, psychoactive drug use and BDSM. Females have lower anal canal pressures and less robust sphincters than males, which may make them more susceptible to incontinence, particularly if coercion is involved.

Congenital defects

Anorectal anomalies and spinal cord defects may be a cause in children. These are usually picked up and operated upon during early life, but continence is often imperfect thereafter. Proctosigmoidoscopy involves the insertion of an endoscope (a long, thin, flexible tube with a camera) into the anal canal, rectum and sigmoid colon. The procedure allows for visualization of the interior of the gut and may detect signs of disease or other problems that could be a cause, such as inflammation, tumors, or scar tissue. Endoanal ultrasound, which some consider the gold standard for detection of anal canal lesions, evaluates the structure of the anal sphincters and may detect occult sphincter tears that otherwise would go unseen.

Functional FI is common. The Rome process published diagnostic criteria for functional FI, which they defined as "recurrent uncontrolled passage of fecal material in an individual with a developmental age of at least four years". The diagnostic criteria are, one or more of the following factors present for the last three months: abnormal functioning of normally innervated and structurally intact muscles, minor abnormalities of sphincter structure or innervation (nerve supply), normal or disordered bowel habits, (i.e., fecal retention or diarrhea), and psychological causes. Furthermore, exclusion criteria are given. These are factors that all must be excluded for a diagnosis of functional FI, and are abnormal innervation caused by lesion(s) within the brain (e.g., dementia), spinal cord (at or below T12), or sacral nerve roots, or mixed lesions (e.g., multiple sclerosis), or as part of a generalized peripheral or autonomic neuropathy (e.g., due to diabetes), anal sphincter abnormalities associated with a multisystem disease (e.g., scleroderma), and structural or neurogenic abnormalities that are the major cause.

Definition

There is no globally accepted definition, "Social continence" has been given various precise definitions for the purposes of research; however, generally it refers to symptoms being controlled to an extent that is acceptable to the individual in question, with no significant effect on their life. There is no consensus about the best way to classify FI, whereas fecal incontinence may be given the definition of involuntary loss of solid or liquid feces which may also be caused by enlarged skin tags, poor hygiene, hemorrhoids, rectal prolapse, and fistula in ano. It may occur together with incontinence of liquids or solids, or it may present in isolation. Flatus incontinence may be the first sign of FI. However, the term anal incontinence is also often used interchangeably as a synonym for FI generally, and use a wider definition for FI which includes

uncontrolled passage of feces or gas.

Fecal leakage, fecal soiling and fecal seepage are minor degrees of FI, and describe incontinence of liquid stool, mucus, or very small amounts of solid stool. They cover a spectrum of increasing symptom severity (staining, soiling, seepage, and accidents). The term pseudoincontinence is used when there is FI in children who have anatomical defects (e.g. enlarged sigmoid colon or anal stenosis).

Clinical measurement

Several severity scales exist. The Cleveland Clinic (Wexner) fecal incontinence score takes into account five parameters that are scored on a scale from zero (absent) to four (daily) frequency of incontinence to gas, liquid, solid, of need to wear pad, and of lifestyle changes.

those continent for solid and liquid stool and also for flatus
those continent for solid and liquid stool but incontinent for flatus (with or without urgency)
those continent for solid stool but incontinent for liquid stool or flatus
those incontinent to formed stool (complete incontinence)

The fecal incontinence severity index is based on four types of leakage (gas, mucus, liquid stool, solid stool) and five frequencies (once to three times per month, once per week, twice per week, once per day, twice or more per day). Other severity scales include AMS, Pescatori, Williams score, Kirwan, Miller score, Saint Mark's score, and the Vaizey scale.

Medication

Pharmacological management may include anti-diarrheal or constipating agents and laxatives or stool bulking agents. Stopping or substituting any previous medication that causes diarrhea may be helpful in some (see table). There is no good evidence for the use of any medications, however.

In people who have undergone gallbladder removal, the bile acid sequestrant cholestyramine may help minor degrees of FI. Bulking agents also absorb water, so may be helpful for those with diarrhea. A common side effect is bloating and flatulence. Topical agents to treat and prevent dermatitis may also be used, such as topical antifungals when there is evidence of perianal candidiasis or occasionally mild topical anti-inflammatory medication. Prevention of secondary lesions is carried out by perineal cleansing, moisturization, and the use of a skin protectant.

Other measures

Evacuation aids (suppositories or enemas) e.g. glycerine or bisacodyl suppositories may be prescribed. People may have a poor resting tone of the anal canal, and consequently may not be able to retain an enema, in which case transanal irrigation (retrograde anal irrigation) may be a better option, as this equipment utilizes an inflatable catheter to prevent loss of the irrigation tip and to provide a water tight seal during irrigation. A volume of lukewarm water is gently pumped into the colon via the anus. People can be taught how to perform this treatment in their own homes, but it does require special equipment. If the irrigation is efficient, the stool will not reach the rectum again for up to 48 hours. However, persistent leaking of residual irrigation fluid during the day may occur and make this option unhelpful, particularly in persons with obstructed defecation syndrome who may have an incomplete evacuation of any rectal contents. Consequently, the best time to carry out the irrigation is typically in the evening, allowing any residual liquid to be passed the next morning before leaving the home. Complications such as electrolyte imbalance and perforation are rare. The effect of transanal irrigation varies considerably. Some individuals experience complete control of incontinence, and others report little or no benefit. Biofeedback therapy varies in the way it is delivered, but it is unknown if one type has benefits over another. Rarely, skin reactions may occur where the electrodes are placed, but these issues typically resolve when the stimulation is stopped. Surgically implanted sacral nerve stimulation may be more effective than exercises, and electrical stimulation and biofeedback may be more effective than exercises or electrical stimulation by themselves.

In a minority of people, anal plugs may be useful for either standalone therapy or in concert with other treatments. Anal plugs (sometimes termed tampons) aim to block the involuntary loss of fecal material, and they vary in design and composition. The surgical options can be considered in four categories: restoration and improvement of residual sphincter function (sphincteroplasty, sacral nerve stimulation, tibial nerve stimulation, correction of anorectal deformity), replacement and imitation of the sphincter or its function (anal encirclement, SECCA procedure, non-dynamic graciloplasty, perianal injectable bulking agents and implantable bulking agents), dynamic sphincter replacement (artificial bowel sphincter, dynamic graciloplasty), antegrade continence enema (Malone procedure), and finally fecal diversion (e.g. colostomy). Females are more likely to develop it than males (63% of those with FI over 30 may be female). 45–50% of people with FI have severe physical or mental disabilities.

Risk factors include age, female gender, urinary incontinence, history of vaginal delivery (non-Caesarean section childbirth), obesity,

Traditionally, FI was thought to be an insignificant complication of surgery, but it is now known that a variety of different procedures are associated with this possible complication, and sometimes at high levels. Examples are midline internal sphincterotomy (8% risk), lateral internal sphincterotomy, fistulectomy, fistulotomy (1852%), hemorrhoidectomy (33%), ileo-anal reservoir reconstruction, lower anterior resection, total abdominal colectomy, ureterosigmoidostomy, Some authors consider obstetric trauma to be the most common cause.

History

While the first mention of urinary incontinence occurs in 1500 BC in the Ebers Papyrus, the first mention of FI in a medical context is unknown. For many centuries, colonic irrigation was the only treatment available. In 1975, Parks describes post anal repair, a technique to reinforce the pelvic floor and EAS to treat idiopathic cases. Endoanal ultrasound is invented in 1991,<!-- The economic cost has not received much attention.

Fecal incontinence while passing gas is known colloquially as a "shart" (a portmanteau of "shit" and "fart").

Netherlands

In the Netherlands, a 2004 study estimated that total costs of patients with fecal incontinence were €2169 per patient per year. Over half of this was productivity loss in work.

United States

In the US, the average lifetime cost (treatment and follow-up) was $17,166 per person in 1996. The average hospital charge for sphincteroplasty was $8555 per procedure. Overall, in the US, the total charges associated with surgery increased from $34 million in 1998 to $57.5 million in 2003. Sacral nerve stimulation, dynamic graciloplasty, and colostomy were all shown to be cost-effective.

Japan

Some insults in Japan relate to incontinence, such as or and , though these have not been in common use since the 1980s.

Law

The case Hiltibran et al v. Levy et al in the United States District Court for the Western District of Missouri resulted in that court issuing an order in 2011. That order requires incontinence briefs funded by Medicaid to be given by the State of Missouri to adults who would be institutionalized without them.

References

External links

Independent continence product advisor