Anismus

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Anismus
Other namesDyssynergic defecation
Anismus.jpg
Specialty Gastroenterology

Anismus or dyssynergic defecation is the failure of normal relaxation of pelvic floor muscles during attempted defecation. It can occur in both children and adults, and in both men and women (although it is more common in women). It can be caused by physical defects or it can occur for other reasons or unknown reasons. Anismus that has a behavioral cause could be viewed as having similarities with parcopresis, or psychogenic fecal retention.[ citation needed ]

Contents

Symptoms include tenesmus (the sensation of incomplete emptying of the rectum after defecation has occurred) and constipation. Retention of stool may result in fecal loading (retention of a mass of stool of any consistency) or fecal impaction (retention of a mass of hard stool). This mass may stretch the walls of the rectum and colon, causing megarectum and/or megacolon, respectively. Liquid stool may leak around a fecal impaction, possibly causing degrees of liquid fecal incontinence. This is usually termed encopresis or soiling in children, and fecal leakage, soiling or liquid fecal incontinence in adults.

Anismus is usually treated with dietary adjustments, such as dietary fiber supplementation. It can also be treated with a type of biofeedback therapy, during which a sensor probe is inserted into the person's anal canal in order to record the pressures exerted by the pelvic floor muscles. These pressures are visually fed back to the patient via a monitor who can regain the normal coordinated movement of the muscles after a few sessions.

Some researchers have suggested that anismus is an over-diagnosed condition, since the standard investigations or digital rectal examination and anorectal manometry were shown to cause paradoxical sphincter contraction in healthy controls, who did not have constipation or incontinence. [1] Due to the invasive and perhaps uncomfortable nature of these investigations, the pelvic floor musculature is thought to behave differently than under normal circumstances. These researchers went on to conclude that paradoxical pelvic floor contraction is a common finding in healthy people as well as in people with chronic constipation and stool incontinence, and it represents a non-specific finding or laboratory artifact related to untoward conditions during examination, and that true anismus is actually rare.

Signs and symptoms

Symptoms include:

Cause

Stylized diagram showing action of the puborectalis sling, and the formation of the anorectal angle. A-puborectalis, B-rectum, C-level of anorectal ring and anorectal angle, D-anal canal, E-anal verge, F-representation of internal and external anal sphincters, G-coccyx & sacrum, H-pubic symphysis, I-Ischium, J-pubic bone. (155) Stylized depiction of action of puborectalis sling.png
Stylized diagram showing action of the puborectalis sling, and the formation of the anorectal angle. A-puborectalis, B-rectum, C-level of anorectal ring and anorectal angle, D-anal canal, E-anal verge, F-representation of internal and external anal sphincters, G-coccyx & sacrum, H-pubic symphysis, I-Ischium, J-pubic bone.

To understand the cause of anismus, an understanding of normal colorectal anatomy and physiology, including the normal defecation mechanism, is helpful. The relevant anatomy includes: the rectum, the anal canal and the muscles of the pelvic floor, especially puborectalis and the external anal sphincter.[ citation needed ]

The rectum is a section of bowel situated just above the anal canal and distal to the sigmoid colon of the large intestine. It is believed to act as a reservoir to store stool until it fills past a certain volume, at which time the defecation reflexes are stimulated. [4] In healthy individuals, defecation can be temporarily delayed until it is socially acceptable to defecate. In continent individuals, the rectum can expand to a degree to accommodate this function.[ citation needed ]

The anal canal is the short straight section of bowel between the rectum and the anus. It can be defined functionally as the distance between the anorectal ring and the end of the internal anal sphincter. The internal anal sphincter forms the walls of the anal canal. The internal anal sphincter is not under voluntary control, and in normal persons it is contracted at all times except when there is a need to defecate. This means that the internal anal sphincter contributes more to the resting tone of the anal canal than the external anal sphincter. The internal sphincter is responsible for creating a watertight seal, and therefore provides continence of liquid stool elements.[ citation needed ]

The puborectalis muscle is one of the pelvic floor muscles. It is skeletal muscle and is therefore under voluntary control. The puborectalis originates on the posterior aspect of the pubic bone, and runs backwards, looping around the bowel.

The point at which the rectum joins the anal canal is known as the anorectal ring, which is at the level that the puborectalis muscle loops around the bowel from in front. This arrangement means that when puborectalis is contracted, it pulls the junction of the rectum and the anal canal forwards, creating an angle in the bowel called the anorectal angle. This angle prevents the movement of stool stored in the rectum moving into the anal canal. It is thought to be responsible for gross continence of solid stool. Some believe the anorectal angle is one of the most important contributors to continence. [5]

Conversely, relaxation of the puborectalis reduces the pull on the junction of the rectum and the anal canal, causing the anorectal angle to straighten out. A squatting posture is also known to straighten the anorectal angle, meaning that less effort is required to defecate when in this position. [6]

Distension of the rectum normally causes the internal anal sphincter to relax (rectoanal inhibitory response, RAIR) and the external anal sphincter initially to contract (rectoanal excitatory reflex, RAER). The relaxation of the internal anal sphincter is an involuntary response. The external anal sphincter, by contrast, is made up of skeletal (or striated muscle) and is therefore under voluntary control. It can contract vigorously for a short time. Contraction of the external sphincter can defer defecation for a time by pushing stool from the anal canal back into the rectum. Once the voluntary signal to defecate is sent back from the brain, the abdominal muscles contract (straining) causing the intra-abdominal pressure to increase. The pelvic floor is lowered causing the anorectal angle to straighten out from ~90o to <15o and the external anal sphincter relaxes. The rectum now contracts and shortens in peristaltic waves, thus forcing fecal material out of the rectum, through the anal canal and out of the anus. The internal and external anal sphincters along with the puborectalis muscle allow the feces to be passed by pulling the anus up over the exiting feces in shortening and contracting actions.[ citation needed ]

In patients with anismus, the puborectalis and the external anal sphincter muscles fail to relax, with resultant failure of the anorectal angle to straighten out and facilitate evacuation of feces from the rectum. These muscles may even contract when they should relax (paradoxical contraction), and this not only fails to straighten out the anorectal angle, but causes it to become more acute and offer greater obstruction to evacuation.

As these muscles are under voluntary control, the failure of muscular relaxation or paradoxical contraction that is characteristic of anismus can be thought of as either maladaptive behavior or a loss of voluntary control of these muscles. Others claim that puborectalis can become hypertrophied (enlarged) or fibrosis (replacement of muscle tissue with a more fibrous tissue), which reduces voluntary control over the muscle.

Anismus could be thought of as the patient "forgetting" how to push correctly, i.e. straining against a contracted pelvic floor, instead of increasing abdominal cavity pressures and lowering pelvic cavity pressures. It may be that this scenario develops due to stress. For example, one study reported that anismus was strongly associated with sexual abuse in women. [7] One paper stated that events such as pregnancy, childbirth, gynaecological descent or neurogenic disturbances of the brain-bowel axis could lead to a "functional obstructed defecation syndrome" (including anismus). [8] Anismus may develop in persons with extrapyramidal motor disturbance due to Parkinson's disease. [9] This represents a type of focal dystonia. [10] Anismus may also occur with anorectal malformation, rectocele, [11] rectal prolapse [12] and rectal ulcer. [12]

In many cases however, the underlying pathophysiology in patients presenting with obstructed defecation cannot be determined. [13]

Some authors have commented that the "puborectalis paradox" and "spastic pelvic floor" concepts have no objective data to support their validity. They state that "new evidence showing that defecation is an integrated process of colonic and rectal emptying suggests that anismus may be much more complex than a simple disorder of the pelvic floor muscles." [13]

Complications

Persistent failure to fully evacuate stool may lead to retention of a mass of stool in the rectum (fecal loading), which can become hardened, forming a fecal impaction or even fecaliths.[ citation needed ]

Liquid stool elements may leak around the retained fecal mass, which may lead to paradoxical diarrhoea and/or fecal leakage (usually known as encopresis in children and fecal leakage in adults). [14] [15] [16] [17]

When anismus occurs in the context of intractable encopresis (as it often does), resolution of anismus may be insufficient to resolve encopresis. [18] For this reason, and because biofeedback training is invasive, expensive, and labor-intensive, biofeedback training is not recommended for treatment of encopresis with anismus.

The walls of the rectum may become stretched, known as megarectum. [19]

Diagnosis

In the Rome IV classification, diagnostic criteria for "functional defecation disorders" are as follows: [20]

2 subcategories exist within the functional defecation disorders category:

For all of these Rome-IV diagnoses, diagnostic criteria must have been fulfilled for the last 3 months with symptom onset at least 6 months prior to diagnosis. [20] The subcategories F3a and F3b are defined by age- and gender-appropriate normal values for the technique. [20]

Previous Rome criteria recommended that anorectal testing is not usually indicated in patients with symptoms until patients have failed conservative treatment (e.g., increased dietary fiber and liquids; elimination of medications with constipating side effects whenever possible).[ citation needed ]

Definition

Several definitions have been offered:

Digital rectal examination

Physical examination can rule out anismus (by identifying another cause) but is not sufficient to diagnose anismus.

Anorectal manometry

The measurement of pressures within the rectum and anus with a manometer (pressure-sensing probe).

Evacuation proctography

defecating proctogram, and MRI defecography

Classification

Anismus can be subcategorized into 4 types based on the results of anorectal manometry testing: [22]

Anismus is classified as a functional defecation disorder. It is also a type of rectal outlet obstruction (a functional outlet obstruction). Where anismus causes constipation, it is an example of functional constipation. Many authors describe an "obstructed defecation syndrome", of which anismus is a cause. [24]

The Rome II classification functional defecation disorders were divided into 3 types, [25] however the symptoms the patient experiences are identical. [26]

It can be seen from the above classification that many of the terms that have been used interchangeably with anismus are inappropriately specific and neglect the concept of impaired propulsion. Similarly, some of the definitions that have been offered are also too restrictive.

Rectal cooling test

The rectal cooling test is suggested to differentiate between rectal inertia and impaired relaxation/paradoxical contraction [27]

Other techniques include manometry, balloon expulsion test, evacuation proctography (see defecating proctogram), and MRI defecography. [28] Diagnostic criteria are: fulfillment of criteria for functional constipation, manometric and/or EMG and/or radiological evidence (2 out of 3), evidence of adequate expulsion force, and evidence of incomplete evacuation. [28] Recent dynamic imaging studies have shown that in persons diagnosed with anismus the anorectal angle during attempted defecation is abnormal, and this is due to abnormal (paradoxical) movement of the puborectalis muscle. [29] [30] [31]

Treatment

Initial steps to alleviate anismus include dietary adjustments and simple adjustments when attempting to defecate. Supplementation with a bulking agent such as psyllium 3500 17 mg per day will make stool more bulky, which decreases the effort required to evacuate. [23] Similarly, exercise and adequate hydration may help to optimise stool form. The anorectal angle has been shown to flatten out when in a squatting position, and is thus recommended for patients with functional outlet obstruction like anismus. [5] If the patient is unable to assume a squatting postures due to mobility issues, a low stool can be used to raise the feet when sitting, which effectively achieves a similar position.[ citation needed ]

Treatments for anismus include biofeedback retraining, botox injections, and surgical resection. Anismus sometimes occurs together with other conditions that limit (see contraindication) the choice of treatments. Thus, thorough evaluation is recommended prior to treatment. [32]

Biofeedback training for treatment of anismus is highly effective and considered the gold standard therapy by many. [18] [33] [34] Others however, reported that biofeedback had a limited therapeutic effect. [35]

Injections of botulin toxin type-A into the puborectalis muscle are very effective in the short term, and somewhat effective in the long term. [36] Injections may be helpful when used together with biofeedback training. [37] [38]

Historically, the standard treatment was surgical resection of the puborectalis muscle, which sometimes resulted in fecal incontinence. Recently, partial resection (partial division) has been reported to be effective in some cases. [35] [39]

Etymology and synonyms

Paradoxical anal contraction during attempted defecation in constipated patients was first described in a paper in 1985, when the term anismus was first used. [40] The researchers drew analogies to a condition called vaginismus, which involves paroxysmal (sudden and short lasting) contraction of pubococcygeus (another muscle of the pelvic floor). These researchers felt that this condition was a spastic dysfunction of the anus, analogous to 'vaginismus'. However, the term anismus implies a psychogenic etiology, which is not true although psychological dysfunction has been described in these patients. Hence:

Latin ani - "of the anus"
Latin spasmus - "spasm"

(Derived by extrapolation with the term vaginismus, which in turn is from the Latin vagina - "sheath" + spasmus - "spasm")

Many terms have been used synonymously to refer to this condition, some inappropriately. The term "anismus" has been criticised as it implies a psychogenic cause. [41] In the most widely accepted classification systems (ICD-11 and Rome-IV, the term "dyssynergic defecation" is preferred. [21] [20] As stated in the Rome II criteria, the term "dyssynergic defecation" is preferred to "pelvic floor dyssynergia" because many patients with dyssynergic defecation do not report sexual or urinary symptoms, [25] meaning that only the defecation mechanism is affected.

Other synonyms include:

See also

Related Research Articles

<span class="mw-page-title-main">Defecation</span> Expulsion of feces from the digestive tract

Defecation follows digestion, and is a necessary process by which organisms eliminate a solid, semisolid, or liquid waste material known as feces from the digestive tract via the anus or cloaca. The act has a variety of names ranging from the common, like pooping or crapping, to the technical, e.g. bowel movement, to the obscene (shitting), to the euphemistic, to the juvenile. The topic, usually avoided in polite company, can become the basis for some potty humor.

<span class="mw-page-title-main">Constipation</span> Bowel dysfunction

Constipation is a bowel dysfunction that makes bowel movements infrequent or hard to pass. The stool is often hard and dry. Other symptoms may include abdominal pain, bloating, and feeling as if one has not completely passed the bowel movement. Complications from constipation may include hemorrhoids, anal fissure or fecal impaction. The normal frequency of bowel movements in adults is between three per day and three per week. Babies often have three to four bowel movements per day while young children typically have two to three per day.

<span class="mw-page-title-main">Fecal incontinence</span> Inability to refrain from defecation

Fecal incontinence (FI), or in some forms, encopresis, is a lack of control over defecation, leading to involuntary loss of bowel contents, both liquid stool elements and mucus, or solid feces. When this loss includes flatus (gas), it is referred to as anal incontinence. 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, altered bowel habits. An estimated 2.2% of community-dwelling adults are affected. However, reported prevalence figures vary. A prevalence of 8.39% among non-institutionalized U.S adults between 2005 and 2010 has been reported, and among institutionalized elders figures come close to 50%.

<span class="mw-page-title-main">Levator ani</span> Broad, thin muscle group, situated on either side of the pelvis

The levator ani is a broad, thin muscle group, situated on either side of the pelvis. It is formed from three muscle components: the pubococcygeus, the iliococcygeus, and the puborectalis.

<span class="mw-page-title-main">Anal fissure</span> Medical condition

An anal fissure is a break or tear in the skin of the anal canal. Anal fissures may be noticed by bright red anal bleeding on toilet paper and undergarments, or sometimes in the toilet. If acute they are painful after defecation, but with chronic fissures, pain intensity often reduces.

<span class="mw-page-title-main">Rectal prolapse</span> Medical condition

A rectal prolapse occurs when walls of the rectum have prolapsed to such a degree that they protrude out of the anus and are visible outside the body. However, most researchers agree that there are 3 to 5 different types of rectal prolapse, depending on whether the prolapsed section is visible externally, and whether the full or only partial thickness of the rectal wall is involved.

<span class="mw-page-title-main">Internal anal sphincter</span> Ring of smooth muscle that surrounds part of the anal canal

The internal anal sphincter, IAS, is a ring of smooth muscle that surrounds about 2.5–4.0 cm of the anal canal. It is about 5 mm thick, and is formed by an aggregation of the smooth (involuntary) circular muscle fibers of the rectum. it terminates distally about 6 mm from the anal orifice.

<span class="mw-page-title-main">Levator ani syndrome</span> Medical condition

Levator ani syndrome is a condition characterized by burning pain or tenesmus of the rectal or perineal area, caused by spasm of the levator ani muscle. The genesis of the syndrome is unknown; however, inflammation of the arcus tendon is a possible cause of levator ani syndrome.

<span class="mw-page-title-main">Defecography</span> Visualisation of the mechanics of a patients defecation

Defecography is a type of medical radiological imaging in which the mechanics of a patient's defecation are visualized in real time using a fluoroscope. The anatomy and function of the anorectum and pelvic floor can be dynamically studied at various stages during defecation.

<span class="mw-page-title-main">Rectum</span> Final portion of the large intestine

The rectum is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. The adult human rectum is about 12 centimetres (4.7 in) long, and begins at the rectosigmoid junction at the level of the third sacral vertebra or the sacral promontory depending upon what definition is used. Its diameter is similar to that of the sigmoid colon at its commencement, but it is dilated near its termination, forming the rectal ampulla. It terminates at the level of the anorectal ring or the dentate line, again depending upon which definition is used. In humans, the rectum is followed by the anal canal which is about 4 centimetres (1.6 in) long, before the gastrointestinal tract terminates at the anal verge. The word rectum comes from the Latin rectumintestinum, meaning straight intestine.

<span class="mw-page-title-main">Human anus</span> External opening of the rectum

In humans, the anus is the external opening of the rectum located inside the intergluteal cleft. Two sphincters control the exit of feces from the body during an act of defecation, which is the primary function of the anus. These are the internal anal sphincter and the external anal sphincter, which are circular muscles that normally maintain constriction of the orifice and which relaxes as required by normal physiological functioning. The inner sphincter is involuntary and the outer is voluntary. Above the anus is the perineum, which is also located beneath the vulva or scrotum.

Rectal pain is the symptom of pain in the area of the rectum. A number of different causes (68) have been documented.

<span class="mw-page-title-main">Anorectal manometry</span> Medical functional test of the anus and rectum

Anorectal manometry (ARM) is a medical test used to measure pressures in the anus and rectum and to assess their function. The test is performed by inserting a catheter, that contains a probe embedded with pressure sensors, through the anus and into the rectum. Patients may be asked to perform certain maneuvers, such as coughing or attempting to defecate, to assess for pressure changes. Anorectal manometry is a safe and low risk procedure.

Rectal discharge is intermittent or continuous expression of liquid from the anus. Normal rectal mucus is needed for proper excretion of waste. Otherwise, this is closely related to types of fecal incontinence 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.

Solitary rectal ulcer syndrome or SRUS is a chronic, benign disorder of the rectal mucosa. It commonly occurs with varying degrees of rectal prolapse. The condition is thought to be caused by different factors, such as long term constipation, straining during defecation, and dyssynergic defecation. Treatment is by normalization of bowel habits, biofeedback, and other conservative measures. In more severe cases various surgical procedures may be indicated. The condition is relatively rare, affecting approximately 1 in 100,000 people per year. It affects mainly adults aged 30–50. Females are affected slightly more often than males. The disorder can be confused clinically with rectal cancer or other conditions such as inflammatory bowel disease, even when a biopsy is done.

Obstructed defecation syndrome is a major cause of functional constipation, of which it is considered a subtype. It is characterized by difficult and/or incomplete emptying of the rectum with or without an actual reduction in the number of bowel movements per week. Normal definitions of functional constipation include infrequent bowel movements and hard stools. In contrast, ODS may occur with frequent bowel movements and even with soft stools, and the colonic transit time may be normal, but delayed in the rectum and sigmoid colon.

Dyssynergia is any disturbance of muscular coordination, resulting in uncoordinated and abrupt movements. This is also an aspect of ataxia. It is typical for dyssynergic patients to split a movement into several smaller movements. Types of dyssynergia include Ramsay Hunt syndrome type 1, bladder sphincter dyssynergia, and anal sphincter dyssynergia.

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.

<span class="mw-page-title-main">Neurogenic bowel dysfunction</span> Human disease involving inability to control defecation

Neurogenic bowel dysfunction (NBD) is the inability to control defecation due to a deterioration of or injury to the nervous system, resulting in faecal incontinence or constipation. It is common in people with spinal cord injury (SCI), multiple sclerosis (MS) or spina bifida.

Low anterior resection syndrome is a complication of lower anterior resection, a type of surgery performed to remove the rectum, typically for rectal cancer. It is characterized by changes to bowel function that affect quality of life, and includes symptoms such as fecal incontinence, incomplete defecation or the sensation of incomplete defecation, changes in stool frequency or consistency, unpredictable bowel function, and painful defecation (dyschezia). Treatment options include symptom management, such as use of enemas, or surgical management, such as creation of a colostomy.

References

  1. Voderholzer, W A; Neuhaus, D A; Klauser, A G; Tzavella, K; Muller-Lissner, S A; Schindlbeck, N E (1 August 1997). "Paradoxical sphincter contraction is rarely indicative of anismus". Gut. 41 (2): 258–262. doi:10.1136/gut.41.2.258. PMC   1891465 . PMID   9301508.
  2. 1 2 3 4 Phillips, [edited by] Steven D. Wexner, Andrew P. Zbar, Mario Pescatori; with a foreword by Robin (2005). Complex anorectal disorders investigation and management. London: Springer. ISBN   978-1852336905.{{cite book}}: |first= has generic name (help)CS1 maint: multiple names: authors list (link)
  3. 1 2 3 Wexner, edited by Andrew P. Zbar, Steven D. (2010). Coloproctology. New York: Springer. ISBN   978-1-84882-755-4.{{cite book}}: |first= has generic name (help)CS1 maint: multiple names: authors list (link)
  4. Shafik, A; Mostafa, RM; Shafik, I; Ei-Sibai, O; Shafik, AA (2006-07-28). "Functional activity of the rectum: A conduit organ or a storage organ or both?". World Journal of Gastroenterology. 12 (28): 4549–52. doi: 10.3748/wjg.v12.i28.4549 . PMC   4125645 . PMID   16874870.
  5. 1 2 Altomare, DF; Rinaldi, M; Veglia, A; Guglielmi, A; Sallustio, PL; Tripoli, G (February 2001). "Contribution of posture to the maintenance of anal continence". International Journal of Colorectal Disease. 16 (1): 51–4. doi:10.1007/s003840000274. PMID   11317698. S2CID   19755817.
  6. Sikirov, D (July 2003). "Comparison of straining during defecation in three positions: results and implications for human health". Digestive Diseases and Sciences. 48 (7): 1201–5. doi:10.1023/a:1024180319005. PMID   12870773. S2CID   7625852.
  7. Leroi, AM; Berkelmans, I; Denis, P; Hémond, M; Devroede, G (July 1995). "Anismus as a marker of sexual abuse. Consequences of abuse on anorectal motility". Digestive Diseases and Sciences. 40 (7): 1411–6. doi:10.1007/bf02285184. PMID   7628260. S2CID   36324110.
  8. 1 2 Kairaluoma, MV (2009). "[Functional obstructed defecation syndrome]". Duodecim; Laaketieteellinen Aikakauskirja. 125 (2): 221–5. PMID   19341037.
  9. Tolosa, E.; Compta, Y. (2006). "Dystonia in Parkinson's disease". Journal of Neurology. 253 (Suppl 7): VII7–VI13. doi:10.1007/s00415-006-7003-6. PMID   17131231. S2CID   21944227.
  10. Mathers, S.; Kempster, P.; Swash, M.; Lees, A. (1988). "Constipation and paradoxical puborectalis contraction in anismus and Parkinson's disease: a dystonic phenomenon?". Journal of Neurology, Neurosurgery, and Psychiatry. 51 (12): 1503–1507. doi:10.1136/jnnp.51.12.1503. PMC   1032764 . PMID   3221217.
  11. Thompson, J.; Chen, A.; Pettit, P.; Bridges, M. (2002). "Incidence of occult rectal prolapse in patients with clinical rectoceles and defecatory dysfunction". American Journal of Obstetrics and Gynecology. 187 (6): 1494–1499, discussion 1499–500. doi:10.1067/mob.2002.129162. PMID   12501052.
  12. 1 2 Velasco, F.; López, R.; Pujol, J.; Sancho, F.; Llauradó, J.; Lluís, F.; Clavé, P. (1998). "The use of anorectal manometry and dynamic proctography in patients for diagnosis of solitary rectal ulcer syndrome". Revista Espanola de Enfermedades Digestivas. 90 (6): 454–458. PMID   9708010.
  13. 1 2 Lubowski, DZ; King, DW (February 1995). "Obstructed defecation: current status of pathophysiology and management". The Australian and New Zealand Journal of Surgery. 65 (2): 87–92. doi:10.1111/j.1445-2197.1995.tb07267.x. PMID   7857236.
  14. Catto-Smith, AG; Nolan, TM; Coffey, CM (September 1998). "Clinical significance of anismus in encopresis". Journal of Gastroenterology and Hepatology. 13 (9): 955–60. doi:10.1111/j.1440-1746.1998.tb00768.x. PMID   9794197. S2CID   23110387.
  15. Hoffmann, BA; Timmcke, AE; Gathright JB, Jr; Hicks, TC; Opelka, FG; Beck, DE (July 1995). "Fecal seepage and soiling: a problem of rectal sensation". Diseases of the Colon and Rectum. 38 (7): 746–8. doi:10.1007/bf02048034. PMID   7607037. S2CID   38351811.
  16. Rao, SS; Ozturk, R; Stessman, M (November 2004). "Investigation of the pathophysiology of fecal seepage". The American Journal of Gastroenterology. 99 (11): 2204–9. doi:10.1111/j.1572-0241.2004.40387.x. PMID   15555003. S2CID   27454746.
  17. van der Hagen, SJ; Soeters, PB; Baeten, CG; van Gemert, WG (September 2011). "Conservative treatment of patients with faecal soiling". Techniques in Coloproctology. 15 (3): 291–5. doi:10.1007/s10151-011-0709-1. PMC   3155048 . PMID   21720889.
  18. 1 2 Nolan T, Catto-Smith T, Coffey C, Wells J (August 1998). "Randomised controlled trial of biofeedback training in persistent encopresis with anismus". Arch. Dis. Child. 79 (2): 131–5. doi:10.1136/adc.79.2.131. PMC   1717674 . PMID   9797593.
  19. Real Martínez, Y; Ibáñez Moya, M; Pérez Mota, A (June 2007). "[Megarectum and anismus: a cause of constipation]". Revista Española de Enfermedades Digestivas. 99 (6): 352–3. doi: 10.4321/s1130-01082007000600009 . PMID   17883300.
  20. 1 2 3 4 5 6 7 8 9 10 11 "Appendix A: Rome IV Diagnostic Criteria for FGIDs". Rome Foundation.
  21. 1 2 "DD92.2 Functional defaecation disorders. ICD-11 for Mortality and Morbidity Statistics". icd.who.int.
  22. 1 2 Bordeianou, Liliana G.; Carmichael, Joseph C.; Paquette, Ian M.; Wexner, Steven; Hull, Tracy L.; Bernstein, Mitchell; Keller, Deborah S.; Zutshi, Massarat; Varma, Madhulika G.; Gurland, Brooke H.; Steele, Scott R. (April 2018). "Consensus Statement of Definitions for Anorectal Physiology Testing and Pelvic Floor Terminology (Revised)". Diseases of the Colon & Rectum. 61 (4): 421–427. doi:10.1097/DCR.0000000000001070. PMID   29521821.
  23. 1 2 3 4 5 6 al., senior editors, Bruce G. Wolff ... et (2007). The ASCRS textbook of colon and rectal surgery. New York: Springer. ISBN   978-0-387-24846-2.{{cite book}}: |first= has generic name (help)CS1 maint: multiple names: authors list (link)
  24. 1 2 Marzouk, Deya. "Obstructed Defaecation Web" . Retrieved 20 August 2012.
  25. 1 2 Bharucha, AE; Wald, A; Enck, P; Rao, S (April 2006). "Functional anorectal disorders". Gastroenterology. 130 (5): 1510–8. doi: 10.1053/j.gastro.2005.11.064 . PMID   16678564.
  26. Rao, SS; Mudipalli, RS; Stessman, M; Zimmerman, B (October 2004). "Investigation of the utility of colorectal function tests and Rome II criteria in dyssynergic defecation (Anismus)". Neurogastroenterology and Motility. 16 (5): 589–96. doi:10.1111/j.1365-2982.2004.00526.x. PMID   15500515. S2CID   26066949.
  27. Shafik, A; Shafik, I; El Sibai, O; Shafik, AA (March 2007). "Rectal cooling test in the differentiation between constipation due to rectal inertia and anismus". Techniques in Coloproctology. 11 (1): 39–43. doi:10.1007/s10151-007-0323-4. PMID   17357865. S2CID   36172856.
  28. 1 2 Berman L, Aversa J, Abir F, Longo WE (July 2005). "Management of disorders of the posterior pelvic floor". Yale J Biol Med. 78 (4): 211–21. PMC   2259151 . PMID   16720016.
  29. Murad-Regadas, S.; Regadas, F.; Barreto, R.; Rodrigues, L.; De Souza, M. (2009). "A novel two-dimensional dynamic anal ultrasonography technique to assess anismus comparing with three-dimensional echodefecography". Colorectal Disease. 11 (8): 872–877. doi:10.1111/j.1463-1318.2009.02018.x. PMID   19681980. S2CID   1888530.
  30. Chu, W.; Tam, Y.; Lam, W.; Ng, A.; Sit, F.; Yeung, C. (2007). "Dynamic MR assessment of the anorectal angle and puborectalis muscle in pediatric patients with anismus: technique and feasibility". Journal of Magnetic Resonance Imaging. 25 (5): 1067–1072. doi: 10.1002/jmri.20914 . PMID   17410575.
  31. Murad-Regadas, S.; Regadas, F.; Rodrigues, L.; Souza, M.; Lima, D.; Silva, F.; Filho, F. (2007). "A novel procedure to assess anismus using three-dimensional dynamic anal ultrasonography". Colorectal Disease. 9 (2): 159–165. doi:10.1111/j.1463-1318.2006.01157.x. PMID   17223941. S2CID   30918501.
  32. Kaye, D; Wenger, N; Agarwal, B (1978). "Pharmacology of intraperitoneal cefazolin in patients undergoing peritoneal dialysis". Antimicrobial Agents and Chemotherapy. 14 (3): 318–21. doi:10.1128/aac.14.3.318. PMC   352457 . PMID   708010.
  33. Chiarioni G, Salandini L, Whitehead WE (July 2005). "Biofeedback benefits only patients with outlet dysfunction, not patients with isolated slow transit constipation". Gastroenterology. 129 (1): 86–97. doi:10.1053/j.gastro.2005.05.015. PMID   16012938.
  34. Rao SS, Seaton K, Miller M, et al. (March 2007). "Randomized controlled trial of biofeedback, sham feedback, and standard therapy for dyssynergic defecation". Clin. Gastroenterol. Hepatol. 5 (3): 331–8. doi:10.1016/j.cgh.2006.12.023. PMID   17368232.
  35. 1 2 Faried, M; El Nakeeb, A; Youssef, M; Omar, W; El Monem, HA (August 2010). "Comparative study between surgical and non-surgical treatment of anismus in patients with symptoms of obstructed defecation: a prospective randomized study". Journal of Gastrointestinal Surgery. 14 (8): 1235–43. doi:10.1007/s11605-010-1229-4. PMID   20499203. S2CID   28441828.
  36. Farid, M.; Youssef, T.; Mahdy, T.; Omar, W.; Moneim, H.; El Nakeeb, A.; Youssef, M. (2009). "Comparative study between botulinum toxin injection and partial division of puborectalis for treating anismus". International Journal of Colorectal Disease. 24 (3): 327–334. doi:10.1007/s00384-008-0609-7. PMID   19039596. S2CID   16943528.; Farid, M.; El Monem, H.; Omar, W.; El Nakeeb, A.; Fikry, A.; Youssef, T.; Yousef, M.; Ghazy, H.; Fouda, E.; El Metwally, T.; Khafagy, W.; Ahmed, S.; El Awady, S.; Morshed, M.; El Lithy, R. (2009). "Comparative study between biofeedback retraining and botulinum neurotoxin in the treatment of anismus patients". International Journal of Colorectal Disease. 24 (1): 115–120. doi:10.1007/s00384-008-0567-0. PMID   18719924. S2CID   26068227.
  37. Joo, J.; Agachan, F.; Wolff, B.; Nogueras, J.; Wexner, S. (1996). "Initial North American experience with botulinum toxin type a for treatment of anismus". Diseases of the Colon and Rectum. 39 (10): 1107–1111. doi:10.1007/BF02081409. PMID   8831524. S2CID   27642905.
  38. Farid, M; El Monem, HA; Omar, W; El Nakeeb, A; Fikry, A; Youssef, T; Yousef, M; Ghazy, H; Fouda, E; El Metwally, T; Khafagy, W; Ahmed, S; El Awady, S; Morshed, M; El Lithy, R (January 2009). "Comparative study between biofeedback retraining and botulinum neurotoxin in the treatment of anismus patients". International Journal of Colorectal Disease. 24 (1): 115–20. doi:10.1007/s00384-008-0567-0. PMID   18719924. S2CID   26068227.
  39. Farid, M.; Youssef, T.; Mahdy, T.; Omar, W.; Moneim, H.; El Nakeeb, A.; Youssef, M. (2009). "Comparative study between botulinum toxin injection and partial division of puborectalis for treating anismus". International Journal of Colorectal Disease. 24 (3): 327–334. doi:10.1007/s00384-008-0609-7. PMID   19039596. S2CID   16943528.
  40. Preston, DM; Lennard-Jones, JE (May 1985). "Anismus in chronic constipation". Digestive Diseases and Sciences. 30 (5): 413–8. doi:10.1007/BF01318172. PMID   3987474. S2CID   20213990.
  41. Rao, Satish S.C. (31 August 2008). "Dyssynergic Defecation and Biofeedback Therapy". Gastroenterology Clinics of North America. 37 (3): 569–586. doi:10.1016/j.gtc.2008.06.011. PMC   2575098 . PMID   18793997.
  42. Bleijenberg, G; Kuijpers, HC (February 1987). "Treatment of the spastic pelvic floor syndrome with biofeedback". Diseases of the Colon and Rectum. 30 (2): 108–11. doi:10.1007/BF02554946. PMID   3803114. S2CID   31492289.
  43. Help for Constipation