Fecal incontinence refers to the unintentional passing of solid or liquid stool, mucus or gases through the anus. This condition results from the inability to control defecation, which, in turn, may be triggered by a myriad of muscular or neurological disorders, vaginal delivery or trauma.
Few patients seek medical attention for acute FI. They are usually ashamed of their condition, come forward only after years of defecation issues. Consequently, dealing with affected individuals requires a great deal of tact. It is important to obtain comprehensive anamnestic data, including but not limited to:
- The medical history of the patient, including prior diagnosis of predisposing diseases and current intake of drugs
- In women, the patient's obstetric history may hint at a possible cause of FI, and details regarding deliveries should be considered
- Information with respect to the duration of FI, the frequency of involuntary bowel movements and whether solid or liquid stools, mucus or gases are lost
- Similarly, it should be inquired on frequency and consistency of voluntarily defecation
- The impact of FI on the patient's quality of life
Patients may or may not be able to relate FI to a trigger, such as surgery, trauma or vaginal delivery, and may report FI of any severity . Involuntary bowel movements may occur occasionally or daily, and may comprise passage of any type of rectal content.
The general examination of an FI patient should include a careful inspection of anal, perineal and genital areas. Dermatitis, hemorrhoidal disease, fissures, scars and fistulae may be detected during a careful visual inspection of these regions. The arrangement of skin folds around the anus may serve as an indicator of the integrity of the anal sphincter muscles . At the same time, such an examination may reveal mucus or pus not to originate from the rectum. This condition may be referred to as pseudoincontinence and patients may not be able to distinguish the latter from FI.
Entire Body System
- Fecal Urgency
Codes R15 Fecal incontinence R15.0 Incomplete defecation R15.1 Fecal smearing R15.2 Fecal urgency R15.9 Full incontinence of feces [icd10data.com]
Fecal urgency also must be differentiated from fecal incontinence because urgency may be related to medical problems other than anal sphincter disruption. [emedicine.medscape.com]
Pelvic irradiation has been shown to be connected to fecal urgency, diarrhea and flatulence [ 23, 24 ]. Neurological disorders are another common cause for FI. [omicsonline.org]
- Rectal Discharge
discharge incontinent of stool (physical finding), unable to restrain bowel movement, rectal discharge incontinent of stool, incontinent of stool, fecal incontinence, Bowel incontinena, Incontinent of faeces, Incontinence fecal, Feces incontinence of [fpnotebook.com]
discharge） 腰大肌徵（英语：Psoas sign） Obturator sign（英语：Obturator sign） Rovsing's sign Hamburger sign（英语：Hamburger sign） Heel tap sign（英语：Heel tap sign） Aure-Rozanova's sign（英语：Aure-Rozanova's sign） Dunphy sign（英语：Dunphy sign） Alder's sign（英语：Alder's sign） [zh.wikipedia.org]
If anamnestic data and findings obtained by physical examination support a diagnosis of FI, further diagnostic measures should be taken:
- An assessment of sensation of the anal and perianal region is recommended. In order to do so, those areas are gently stroked with a cotton swab. In healthy individuals, the external anal sphincter will contract in response to the induction of the anocutaneous reflex, which is also referred to as anal wink reflex. This reflex may be disturbed by spinal cord lesions.
- A digital examination allows for the detection of anatomic anomalies and an estimation of resting sphincter pressure. Dysfunction of the anal sphincter is often associated with a significant decrease in resting sphincter pressure. Additionally, patients should be requested to contract their external anal sphincter, so the examiner can assess its tone upon voluntary inhibition of bowel movements.
- In women, it is necessary to examine the vagina and to evaluate the condition of perineal tissues. The former may be realized by using a speculum, the latter requires a manual examination, possibly simultaneous to a digital examination of the rectum. This approach may reveal pelvic organ prolapse, reduced perineal body thickness or hypermobility as well as anal sphincter disruption.
- In order to evaluate the condition of anal and rectal mucosa, to visualize inflammation and anatomical anomalies, endoanal ultrasonography has to be carried out. To date, this approach is considered the gold standard for evaluating anal sphincter pathology .
- Despite previous estimations of resting and voluntary anal sphincter pressures, anal manometry is generally indicated to obtain objective values regarding these parameters. This technique also allows for an assessment of the rectoanal inhibitory reflex and the rectoanal contractile reflex.
- Defecography allows for the visualization of pelvic floor, rectal and anal function during bowel movements. It usually involves an application of barium sulfate and fluoroscopy, but may also be carried out using magnetic resonance imaging.
- Upon suspicion of pudendal neuropathy, pudendal nerve terminal motor latency may be ascertained. Delayed responses indicated nerve damage .
The primary aim of FI treatment is to normalize quantity and quality of stools. Patients may be advised to keep a stool diary in order to facilitate the monitoring of response to dietary adjustments, drugs and similar measures. In this context, an increased fiber content of foods and constipating medication like loperamide are most commonly recommended . FI patients have been reported to benefit from anal sphincter exercises and biofeedback, but conclusive results cannot yet be provided to this end . Patients who don't respond to the aforementioned treatment options may be considered for sacral nerve stimulation. In determined cases, surgery may be indicated; sphincter repair, insertion of an artificial bowel sphincter, dynamic graciloplasty and fecal diversion shall be mentioned exemplarily . The ideal approach to FI treatment depends on the cause of incontinence, and causative treatment is to be preferred over long-term symptomatic therapy.
The patient's prognosis largely depends on the underlying disease and on the severity of tissue damage. In general, longer times since FI onset negatively affect the outcome, while the preservation of rectoanal reflexes and the use of constipating medication have been related to a better prognosis . The majority of studies regarding the outcome after diagnosis of FI focus on a particular group of patients or on a determined therapeutic approach, and consequently, general data are scarce. In any case, the patient's quality of life may be increased by psychological counseling.
Many diseases may be associated with FI, with muscular or neurological disorders that impede voluntary contraction and relaxation of the anal sphincter muscles being among the most common causes of involuntary bowel movements. In this context, developmental defects, metabolic and degenerative diseases as well as trauma account for the majority of cases. In detail, the following conditions have repeatedly been related to FI:
- Spina bifida, particular in case of myelomeningocele or myeloschisis
- Diabetes mellitus and diabetic neuropathy, especially if serum glucose levels are poorly controlled
- Multiple sclerosis
- Degeneration of the nervous system
- Inflammatory bowel disease
- Colitis, proctitis
- Infestation with intestinal parasites
- Vaginal delivery and obstetric trauma
- Spinal cord trauma
- Colorectal or anorectal surgery
Furthermore, certain conditions and diseases are more prevalent in FI patients than in the general population :
- Old age
- Overweight and obesity
- Pelvic organ prolapse
- Urinary incontinence
- Combined diarrhea and constipation
- Pelvic radiation
The aforementioned predisposing factors and comorbidities may be mutually dependent, e.g., obese individuals have a higher risk of diabetes mellitus and hypertension; the prevalence of osteoarthritis increases with age. Consequently, it is not uncommon for FI patients to belong to more than one at-risk groups.
According to a study realized in the United Kingdom, passive incontinence, urge incontinence, and combined passive and urge incontinence account for equal shares of FI cases. Soiling is less frequently reported . It has been estimated that 8% of the adult population suffers from any of those types of FI, but few people affected seek medical advise  . This is due to the fact that patients are very reluctant to provide information about quantity and quality of their stools, and to report any issue with defecation. On the other hand, health care givers may be indisposed to query their patients accordingly. Available epidemiological data thus have to be interpreted with care. With regards to the age distribution of FI, most studies state the mean age of affected individuals to be over 50 years . Prevalence rates increase with age and may amount to almost 20% in patients aged 85 years and older. Women are more susceptible to FI than men, mainly due to the risk of developing FI due to obstetric trauma.
Anal continence depends on the complex interaction of muscular and neurological structures, namely on anal sphincter muscles, pelvic floor muscles as well as pudendal nerve, pelvic splanchnic nerves and superior centers of the enteric and central nervous system. The internal anal sphincter is part of the circular smooth muscle layer of the rectum and accounts for resting sphincter pressure, while the external anal sphincter forms part of the levator ani muscles and may be contracted voluntarily to augment sphincter pressure . Pelvic floor muscles contribute to sphincter pressure and help to maintain the angle of approximately 90° between rectum and anus. With regards to the anatomical structures forming the seal, mucosal folds and corpus cavernosum recti have to be considered. Developmental defects, traumatic lesions or any other condition that leads to dysfunction of the aforementioned elements may result in FI.
Furthermore, defecation may be induced by the rectoanal inhibitory reflex: Rectal distention is associated with a decrease in resting sphincter pressure as mediated by the internal anal sphincter and thus, large quantities of feces accumulating in the rectum will eventually trigger a bowel movement. Since this reflex merely depends on the myenteric plexus, it is not affected by lesions of the central nervous system. However, impairment of the myenteric plexus may interfere with defecation, and such is the case in Hirschsprung's disease, chagasic megacolon and similar disorders. On the other hand, rectal distention is related to the rectoanal contractile reflex, which refers to an increase in sphincter pressure by means of contraction of the external anal sphincter. This reflex is triggered by sudden increases of intraabdominal pressure, e.g., while coughing or laughing . Accordingly, a blunted rectoanal contractile reflex may contribute to FI. Such is the case in patients suffering from pudendal neuropathy.
Despite extensive knowledge regarding the physiology of anal continence, a myriad of questions remains. For instance, it is not known how rectal contents are perceived and how alterations of sensory inputs contribute to FI. Similarly, it is not understood why women who sustain obstetric trauma as young adults don't usually develop FI before entering menopause.
Determined conditions that predispose for FI may be prevented. In this line, the interested reader is referred to the respective articles dealing with diabetes mellitus, inflammatory bowel disease, colitis, proctitis, obesity, hemorrhoids and others. Adherence to good clinical practice is highly recommended to obstetricians, surgeons and other physicians who treat patients at risk of FI. Episiotomy should not be carried out without proper indication. Furthermore, it has been proposed to prefer a Cesarean section over vaginal delivery in women who present with additional risk factors of FI . Women are to be advised to train pelvic floor muscles during about a year after childbirth.
The inability to control defecation is associated with fecal incontinence (FI), i.e., the unintentional passing of stool, mucus or gases through rectum and anus. The anal sphincter muscles play an important role in sealing the anus, but loss of sphincter control or pathologies that interfere with withholding feces despite preserved sphincter function may cause involuntary bowel movements. In this context, the following disorders may lead to FI :
- Changes in quantity and quality of stool
- Functional disorders
- Structural disturbances
These conditions may be associated with passive incontinence, urge incontinence or soiling. This distinction refers to the patient's awareness of defecation, and an individual patient may experience more than one type of FI. FI is typically diagnosed in the elderly and is indeed the second leading cause for nursing home placement in the United States . However, FI constitutes not only a physical and economic burden but also has a psychological strain on the patient and their caretakers .
Fecal incontinence (FI) refers to the inability to control bowel movements, resulting in the unintentional passing of stool, mucus or gases through rectum and anus. It has been estimated that 8% of the adult population suffers from any type of FI, and this value may be explained by the high prevalence of diseases that may cause FI: Diabetes mellitus, inflammatory bowel disease, colitis, proctitis, obesity, hemorrhoids and obstetric trauma are at the top of a long list of such conditions. In order to treat FI, the physician needs to carry out a visual inspection and functional tests. Fortunately, treatment options are available for many forms of FI, and scientific studies show that patients who undergo therapy may increase their quality of life.
- Buhmann H, Nocito A. [Update on fecal incontinence]. Praxis (Bern 1994). 2014; 103(22):1313-1321.
- Ng KS, Sivakumaran Y, Nassar N, Gladman MA. Fecal Incontinence: Community Prevalence and Associated Factors--A Systematic Review. Dis Colon Rectum. 2015; 58(12):1194-1209.
- Landefeld CS, Bowers BJ, Feld AD, et al. National Institutes of Health state-of-the-science conference statement: prevention of fecal and urinary incontinence in adults. Ann Intern Med. 2008; 148(6):449-458.
- Engel AF, Kamm MA, Bartram CI, Nicholls RJ. Relationship of symptoms in faecal incontinence to specific sphincter abnormalities. Int J Colorectal Dis. 1995; 10(3):152-155.
- Remes-Troche JM, Rao SS. Neurophysiological testing in anorectal disorders. Expert Rev Gastroenterol Hepatol. 2008; 2(3):323-335.
- Rao SS. Pathophysiology of adult fecal incontinence. Gastroenterology. 2004; 126(1 Suppl 1):S14-22.
- Bols E, Hendriks E, de Bie R, Baeten C, Berghmans B. Predictors of a favorable outcome of physiotherapy in fecal incontinence: secondary analysis of a randomized trial. Neurourol Urodyn. 2012; 31(7):1156-1160.
- Hayden DM, Weiss EG. Fecal incontinence: etiology, evaluation, and treatment. Clin Colon Rectal Surg. 2011; 24(1):64-70.
- Chin K. Obstetrics and fecal incontinence. Clin Colon Rectal Surg. 2014; 27(3):110-112.
- Abdool Z, Sultan AH, Thakar R. Ultrasound imaging of the anal sphincter complex: a review. Br J Radiol. 2012; 85(1015):865-875.
- Norton C, Cody JD. Biofeedback and/or sphincter exercises for the treatment of faecal incontinence in adults. Cochrane Database Syst Rev. 2012; (7):Cd002111.
- Ong JP, Edwards GJ, Allison MC. Mode of delivery and risk of fecal incontinence in women with or without inflammatory bowel disease: questionnaire survey. Inflamm Bowel Dis. 2007; 13(11):1391-1394.