Instruct: Given a question, retrieve relevant passages that answer the question.
Query: What is the number one cause of fecal incontinence?
FI is a sign or a symptom, not a diagnosis,[7] and represents an extensive list of causes. Usually, it is the result of a complex interplay of several coexisting factors, many of which may be simple to correct.[7] Up to 80% of people may have more than one abnormality that is contributing.[8] Deficits of individual functional components of the continence mechanism can be partially compensated for a certain period of time, 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.[1][9] The most common factors in the development are thought to be obstetric injury and after effects of anorectal surgery, especially those involving the anal sphincters and hemorrhoidal vascular cushions.[1] The majority of incontinent persons over the age of 18 fall into one of several groups: those with structural anorectal abnormalities (sphincter trauma, sphincter degeneration, perianal fistula, rectal prolapse), neurological disorders (multiple sclerosis, spinal cord injury, spina bifida, stroke, etc.), constipation/fecal loading (presence of a large amount of feces in the rectum with stool of any consistency), cognitive and/or behavioral dysfunction (dementia, learning disabilities), diarrhea, inflammatory bowel diseases (e.g. ulcerative colitis, Crohn's disease), irritable bowel syndrome, disability related (people who are frail, acutely unwell, or have chronic/acute disabilities), and those cases which are idiopathic (of unknown cause).[7][10] Diabetes mellitus is also known to be a cause, but the mechanism of this relationship is not well understood.[11]
General Audience: Bladder retraining, Urinary Catheterization of Men and Women, Fecal Incontinence, Incontinence and Odor Control, Overactive bladder
In fecal incontinence (FI), surgery may be carried out if conservative measures alone are not sufficient to control symptoms. There are many surgical options described for FI, and they can be considered in 4 general groups. 
Pascual et al. (2011) revised the follow up results of the first 50 people that submit to sacral nerve stimulation (SNS) to treat fecal incontinence in Madri (Spain). The most common cause for the fecal incontinence was obstetric procedures, idiopathic origin and prior anal surgery, and all these people were refractory to the conservative treatment. The procedure consisted of placing a temporary pulse generator connected to a unilateral electrode at S3 or S4 foramen for 2–4 weeks. After it was confirmed that the SNS was decreasing the incontinence episodes, the patients received the definitive electrode and pulse generator that was implanted in the gluteus or in the abdomen. Two patients did not show improvement in the first step and did not receive the definitive stimulator. Mean follow up was 17.02 months and during this time the patients showed improvement in the voluntary contraction pressure and reduction of incontinence episodes. Complications were two cases of infection, two cases with pain and one broken electrode. Therefore, although the reason the SNS is effective is unknown, this procedure had satisfactory results in these clinical cases with a low incidence of complications, and the study concluded that it was a good option for treatment of anal incontinence.
The relative effectiveness of surgical options for treating fecal incontinence is not known. A combination of different surgical and non-surgical therapies may be optimal.
Risk factors include age, female gender, urinary incontinence, history of vaginal delivery (non-Caesarean section childbirth), obesity,[25] prior anorectal surgery, poor general health and physical limitations. Combined urinary and fecal incontinence is sometimes termed double incontinence, and it is more likely to be present in those with urinary incontinence.[43]
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.[5]
Surgery is most often successful for people who still have some control over their bowel movements. If the anal sphincter is damaged, surgery may correct the prolapse but not be able to completely correct fecal incontinence (lack of control of bowel movements). Fecal incontinence can both potentially improve or worsen after prolapse surgery.
Fecal incontinence, the involuntary loss of stool and flatus release afflicting mainly elderly people, can also be treated with sacral nerve stimulation as long as patients have intact sphincter muscles. The FDA approved the approach for treating the fecal incontinence in March 2011. The etiology is not well understood yet and both conservative treatments (like antidiarrheics, special diet and biofeedback) and surgical treatments for this disorder are not regarded as ideal options.
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.[5]
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.[1] The Park's incontinence score uses four categories:
Pelvic floor dysfunction may include any of a group of clinical conditions that includes urinary incontinence, fecal incontinence, pelvic organ prolapse, sensory and emptying abnormalities of the lower urinary tract, defecatory dysfunction, sexual dysfunction and several chronic pain syndromes, including vulvodynia. The three most common and definable conditions encountered clinically are urinary incontinence, anal incontinence and pelvic organ prolapse.
It is usually considered a form of irritant contact dermatitis. The word "diaper" is in the name not because the diaper itself causes the rash but rather because the rash is associated with diaper use, being caused by the materials trapped by the diaper (usually feces). Allergic contact dermatitis has also been suggested, but there is little evidence for this cause. In adults with incontinence (fecal, urinary, or both), the rash is sometimes called incontinence-associated dermatitis (IAD).
Anal carcinoma is much less common than colorectal cancer. The most common form is squamous cell carcinoma, followed by adenocarcinoma and melanoma. SCC usually occurs in the anal canal, and more rarely on the anal margin. Anal margin SCC presents as a lesion with rolled, everted edges and central ulceration. Symptoms include a painful lump, bleeding, pruritus ani, tenesmus, discharge or possibly fecal incontinence. SSC in the anal canal most commonly causes bleeding, but may also cause anal pain, a lump, pruritus ani, discharge, tenesmus, change in bowel habits and fecal incontinence. Because these symptoms are so unspecific, and because symptoms of anal carcinoma may not always be typical, this can lead to delays in diagnosis.
Finally, a small number of cases of incontinence are caused by physical problems in the urinary system in children. A condition known as urinary reflux or vesicoureteral reflux, in which urine backs up into one or both ureters, can cause urinary tract infections and incontinence. Rarely, a blocked bladder or urethra may cause the bladder to overfill and leak. Nerve damage associated with the birth defect spina bifida can cause incontinence. An ectopic ureter, a misplacement of the ureter outside the bladder, can also commonly cause incontinence. In these cases, the incontinence can appear as a constant dribbling of urine.
Level 3: Probably efficacious. This designation requires multiple observational studies, clinical studies, waitlist-controlled studies, and within subject and intrasubject replication studies that demonstrate efficacy. Yucha and Montgomery (2008) assigned alcoholism and substance abuse, arthritis, diabetes mellitus, fecal disorders in children, fecal incontinence in adults, insomnia, pediatric headache, traumatic brain injury, urinary incontinence in males, and vulvar vestibulitis (vulvodynia) to this category.
The main concern with surgery is the development of anal incontinence. Anal incontinence can include inability to control gas, mild fecal soiling, or loss of solid stool. Some degree of incontinence can occur in up to 45 percent of patients in the immediate surgical recovery period. However, incontinence is rarely permanent and is usually mild. The risk should be discussed with one's surgeon.
The medical definition of fecal incontinence is the incapacity to voluntarily hold feces in the rectum. There are two subgroups to those with fecal incontinence: real fecal incontinence and pseudoincontinence.
Diversion colitis is inflammation of the section of gut through which stool no longer passes. This condition arises because normally the lining of the gut obtains some of its nutrients from the fecal stream. This condition may cause a foul smelling, mucous rectal discharge from the distal, unused colon.
Urinary incontinence and fecal incontinence have been linked to all methods of childbirth, with the incidence of urinary incontinence at 6 months postpartum being 3-7% and fecal incontinence 1-3%.
Rectal discharge is intermittent or continuous expression of liquid from the anus (per rectum). Normal rectal mucus is needed for proper excretion of waste. Otherwise, this is closely related to types of fecal incontinence (e.g. fecal leakage) but the term rectal discharge does not necessarily imply degrees of incontinence. Types of fecal incontinence that produce a liquid leakage could be thought of as a type of rectal discharge.
Different types of discharge are described. Generally "rectal discharge" refers to either a mucous or purulent discharge, but, depending upon what definition of rectal discharge is used, the following could be included:
Functional FI is common.[23] 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 4 years". The diagnostic criteria are, one or more of the following factors present for the last 3 months: abnormal functioning of normally innervated and structurally intact muscles, minor abnormalities of sphincter structure/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 which 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.[24]
There is a continuous spectrum of different clinical presentations from incontinence of flatus (gas), through incontinence of mucus or liquid stool, to solids. The term anal incontinence often is used to describe flatus incontinence,[7] however it is also used as a synonym for FI generally. 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.[5] Once continence to flatus is lost, it is rarely restored.[7] Anal incontinence may be equally disabling as the other types.[25] 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, soilage, seepage and accidents).[1] Rarely, minor FI in adults may be described as encopresis. Fecal leakage is a related topic to rectal discharge, but this term does not necessarily imply any degree of incontinence. Discharge generally refers to conditions where there is pus or increased mucus production, or anatomical lesions that prevent the anal canal from closing fully, whereas fecal leakage generally concerns disorders of IAS function and functional evacuation disorders which cause a solid fecal mass to be retained in the rectum. Solid stool incontinence may be called complete (or major) incontinence, and anything less as partial (or minor) incontinence (i.e. incontinence of flatus (gas), liquid stool and/or mucus).[5]
1 - those continent for solid and liquid stool and also for flatus. 2 - those continent for solid and liquid stool but incontinent for flatus (with or without urgency). 3 - those continent for solid stool but incontinent for liquid stool or flatus. 4 - those incontinent to formed stool (complete incontinence).[29]
Fecal incontinence (FI), also known as anal incontinence, 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 usually there is more than one deficiency of these mechanisms for incontinence to develop. 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),[1] and receptive anal sex.[2][3][4] An estimated 2.2% of community dwelling adults are affected.[5]