Acs0516 Motility Disorders 2005


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Acs0516 Motility Disorders 2005

  1. 1. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 1 16 MOTILITY DISORDERS Nancy N. Baxter, M.D., Ph.D., F.R.C.S.C., F.A.S.C.R.S., and Robert D. Madoff, M.D., F.A.C.S., F.A.S.C.R.S. Surgeons commonly encounter patients with gastrointestinal ineum (through digitation of the vagina or rectum) to achieve motility disorders.The management of such patients is frequently complete evacuation. challenging, in that the etiology of the disorder is often multifac- Diet can contribute significantly to constipation. Because high- torial. Furthermore, even when surgical therapy is appropriate, fiber foods tend to increase stool bulk and frequency, detailed management of symptoms remains a key component of effective information on dietary fiber intake should be obtained. Because treatment. dehydration increases fluid resorption from stool and thereby In what follows, we discuss two of the most common motility results in the formation of hard stools, total daily fluid intake disorders, constipation and fecal incontinence. Although constipa- should be determined as well. A specific effort should be made to tion usually is not treated surgically, surgeons regularly see patients assess intake of fluids that contain caffeine, which exerts a diuretic with this presenting symptom. It is therefore critical that surgeons effect. Most patients with long-standing constipation will already have a practical method of diagnosing and managing the primary have tried some form of self-medication. Such attempts should be and secondary causes of constipation. Fecal incontinence is an documented, both to help assess the severity of the symptom and understudied and undertreated condition that can have a dramat- to determine the likelihood of response to simple measures. ic impact on quality of life. Effective treatment of incontinence has Various other diseases and certain common medications [see a dramatic positive influence on patients’ lives; thus, it is important Table 1] also can cause or contribute to constipation. When such for surgeons to have both an effective approach to diagnosis and factors are present, treating the underlying condition or changing an informed awareness of the various therapeutic options available medications can result in substantial improvement. Therefore, a (including experimental treatments). thorough past medical history and an accurate medication history are essential. A family history of colonic neoplasia or inflammatory bowel disease is potentially suggestive and may lead to a more Constipation intensive search for secondary causes.Victims of physical or sexual abuse may present with constipation; however, they are unlikely to CLINICAL EVALUATION mention the abuse if not directly questioned about the possibility. History Physical Examination Constipation is the most common digestive complaint, with as During physical examination, it is important to make a quick much as 20% of the population reporting this symptom.1 The assessment of the patient’s nutritional status. In general, patients meaning of the term constipation, however, is variable: when with idiopathic constipation should not appear malnourished; the patients describe themselves as constipated, they may be referring appearance of malnutrition should prompt a more extensive to decreased stool frequency, reduced stool volume, altered stool search for a secondary cause. An abdominal examination should consistency, or difficulty with defecation.2 Accordingly, when a be conducted to look for any significant abdominal distention, patient presents with a complaint of constipation, a thorough his- tenderness, or masses. Distention is a common and expected find- tory of the presenting illness is essential [see Figure 1]. ing with idiopathic constipation, but significant tenderness or The patient should be asked about the frequency of bowel masses should prompt a full investigation. movements, the volume of stool per movement, the caliber of the All patients presenting with constipation should undergo a rec- stool, and, in particular, any changes in bowel habits over time. tal examination. The anus should be examined for evidence of Patients with idiopathic constipation tend to have long-standing scarring or stricture. A digital rectal examination should be done problems, with no abrupt change in bowel habits.Thus, if the his- to assess anal tone; high anal tone and inability to increase pres- tory reveals constipation of sudden onset, an underlying cause sure when asked to squeeze are common findings in patients with (e.g., cancer) is more likely and should be sought. Other impor- obstructed defecation resulting from a nonrelaxing puborectalis. tant symptoms that should lead to a search for a secondary cause An effort should be made to look for any anterior defect in the rec- are weight loss, anorexia, nausea and vomiting, rectal bleeding, tovaginal septum, which would indicate the presence of a recto- changes in stool caliber, and fever. The patient should always be cele; such a defect, if present, may be made more prominent by asked about previous colon cancer screening or other GI investi- having the patient strain.The finding of a rectal mass warrants fur- gations. Although chronic constipation is common, severe consti- ther investigation. pation that has been present since early childhood should alert INVESTIGATIVE STUDIES the clinician to the possibility of undiagnosed short-segment Hirschsprung disease; this rare diagnosis is easily missed if it is In general, diagnostic studies are conducted to rule out an not given appropriate consideration. Other symptoms may be underlying cause of constipation (e.g., partially obstructing colon indicative of an outlet problem (e.g., rectocele or nonrelaxing cancer) and to diagnose specific disorders associated with severe puborectalis syndrome); such symptoms include requiring a pro- constipation (e.g., a nonrelaxing puborectalis and slow-transit longed period to evacuate stool from the rectum, a feeling of constipation). Therefore, the choice of investigative studies incomplete rectal emptying, and the need to support the per- should be individualized according to the clinical situation. In
  2. 2. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 2 Patient presents with constipation Evaluate patient. History: Assess nature and frequency of stools. Determine if problem is chronic or of recent onset. Consider possible medical or pharmacologic underlying causes. Explore patient self-medication. Physical examination: Assess nutritional status. Perform complete abdominal examination and thorough rectal examination. Laboratory tests: Obtain on individualized basis. Recent onset of constipation or Patient has mild to Patient has severe Patient has constipation significant associated symptoms moderate idiopathic long-standing associated with significant suggest underlying cause constipation constipation abdominal pain but no identifiable secondary cause Weight loss, anorexia, nausea and vomiting, rectal bleeding, altered Constipation-predominant irritable Initiate dietary and lifestyle bowel syndrome may be appropriate stool caliber, and fever may signal modifications: exercise, diagnosis. Treat conservatively an underlying condition. increased fiber intake, initially; if such measures fail, Rule out malignancy with laxatives (emollient, colonoscopy. consider tegaserod (in female stimulant, and osmotic). patients). Consider laboratory tests. Constipation Constipation is Underlying cause No underlying responds to refractory to is identified cause is treatment treatment identified Treat underlying cause by treating the disease or changing the offending Initiate advanced testing to look for underlying cause: medication. • Transit studies (to rule out slow-transit constipation) • Pelvic floor studies (to rule out obstructed defecation from nonrelaxed puborectalis) Patient has nonrelaxing puborectalis Patient has slow-transit constipation Patient has severe idiopathic constipation Treat with biofeedback or injection of Attempt maximal medical management first. Provide supportive management. botulinum toxin. If such management fails, perform subtotal Osmotic laxatives (especially PEG Consider experimental techniques colectomy with ileorectal anastomosis. compounds) are likely to yield benefit. (electrogalvanic and sacral nerve stimulation). Figure 1 Algorithm outlines workup and management of constipation. patients with mild symptoms and poor dietary habits who have inal masses, or anemia), colonoscopy is necessary, irrespective of no indications of any secondary causes of constipation, no inves- the patient’s age or history of previous colonic investigations. tigations need be done on a routine basis. In patients with severe Patients with other secondary causes of constipation (e.g., constipation, however, serum calcium concentrations, thyroid hypothyroidism and hypercalcemia) often respond to treatment of function tests, hemoglobin concentrations, glucose levels, serum the underlying disease or manipulation of medications. If such electrolyte levels, and creatinine concentrations may be helpful. measures are ineffective, the constipation should be treated symp- tomatically, in much the same fashion as idiopathic constipation is. Constipation with Suspected Underlying Cause Patients requiring long-term opioid administration for pain control Whenever any of the findings from the history or the physical generally experience constipation as a side effect, and this effect examination indicate a possible secondary cause of constipation, fur- does not dissipate with time. Thus, many of these patients will ther investigation is mandatory. In particular, if a patient presents require laxative therapy for the duration of their opioid use.3 with any sign, symptom, or laboratory test result consistent with colorectal cancer (e.g., a sudden change in bowel habits, blood in Mild to Moderate Idiopathic Constipation the stool, weight loss, anorexia, a suggestive family history, abdom- In patients who have mild to moderate symptoms and no
  3. 3. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 3 Table 1—Causes of Secondary Constipation Severe, Long-standing Constipation or Refractory Constipation In patients who have very severe constipation or in whom med- Spinal cord injury ical management fails, further investigative tests are warranted. Parkinson disease These tests are conducted to classify patients into three categories, Multiple sclerosis Neuromuscular each of which calls for a different treatment approach: (1) slow- disorders Stroke Autonomic neuropathy/diabetes transit constipation, (2) nonrelaxing puborectalis, and (3) normal- Depression transit constipation.4 The initial investigations should include Hirschsprung disease assessment of colonic transit time to determine if slow-transit con- stipation is present, as well as evaluation of pelvic floor function to Hypercalcemia determine if a nonrelaxing puborectalis is present. Hyperparathyroidism There are two main methods for evaluating colonic transit: the Metabolic Hypothyroidism abnormalities radiopaque marker study and colonic scintigraphy. Both tests have Multiple endocrine neoplasia type IIB Chronic renal failure advantages and disadvantages. In general, the choice between them depends on local expertise; the radiopaque marker study is Opioids more widely available. For the radiopaque marker study, 20 Anticholinergics (tricyclic antidepressants, levodopa, radiopaque markers (prepackaged in gelatin capsules) are ingest- antipsychotics) ed, and an abdominal x-ray (which includes the pelvis) is taken on Supplements (iron, calcium) Medications Antacids (calcium- or aluminum-containing) day 5. The patient abstains from laxatives for the duration of the Anticonvulsants (phenytoin, valproic acid) study. At 3 days, most patients with normal transit have excreted Antihypertensives (calcium channel blockers, diuretics, more than 80% of the markers; however, because there is sub- clonidine) stantial variation among asymptomatic persons, only patients who Cholestyramine retain more than 20% of the markers for at least 5 days are con- Pregnancy sidered to have abnormal transit. Abnormal transit may be Amyloidosis demonstrated either throughout the colon or within a limited por- Others Scleroderma tion thereof (most commonly, the sigmoid and the rectum) [see Chagas disease Figure 2]. Anorexia nervosa Colonic scintigraphy shares certain principles with the radiopaque marker study. Patients ingest a meal containing a radioactive isotope, and abdominal images are obtained with a findings from the history or the physical examination that would gamma camera at 12, 24, and 48 hours. The results provide a indicate a secondary cause, extensive investigations are not nec- quantitative assessment of colonic transit. In addition, unlimited essary. Routine colonoscopy is not mandatory for patients numbers of images may be taken with the single isotope dose, and younger than 50 years. For patients older than 50 years, the this feature of the test may be especially useful in children. For baseline risk of colorectal cancer is sufficiently high that screen- optimal accuracy, this technique requires standardization, and its ing colonoscopy is recommended even in the absence of symp- availability is generally limited to centers with specific interest and toms. These older patients should therefore undergo routine expertise in it. colonoscopy, and many authors recommend that patients Pelvic floor studies are valuable for ruling out obstructed defe- younger than 50 years undergo routine flexible sigmoidoscopy. cation as a cause of constipation. The balloon expulsion test can Random endoscopic biopsies are unnecessary, because idiopath- be performed in the office as an initial screening measure.5 A bal- ic constipation is not associated with abnormalities on routine loon filled with 50 ml of water is attached to tubing and placed in processing of mucosal biopsies. the rectum; patients with a nonrelaxing puborectalis generally can- a b Figure 2 Illustrated are characteristic colonic transit study findings 5 days after ingestion of radiopaque markers for (a) pancolonic slow-transit constipation and (b) outlet obstruction.
  4. 4. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 4 a b c Sacrum Fecal Bolus Rectus Rectum Muscles Pubic Arch Puborectalis External Levator Ani Internal Muscle Anal Sphincter Muscle Anal Sphincter Figure 3 Schematic representation of normal defecation depicts (a) initial contraction of pelvic floor muscles with urge to defecate, (b) relaxation of puborectalis and external sphincter, and (c) relaxation of internal sphincter and evacuation of stool with rectal contraction. not expel the balloon from the rectum in 1 minute while sitting on the pelvic floor to relax appropriately (or paradoxical contraction a commode. It should be kept in mind, however, that as many as of the pelvic floor) with defecation. The cause of this condition is 12% of patients with normal pelvic floor function will have diffi- not known; however, the syndrome is thought to be acquired over culty with balloon expulsion in this setting.6 time. Patients with an underlying neurologic disorder (e.g., multi- A thorough pelvic floor evaluation is best conducted in a ple sclerosis or Parkinson disease) are prone to spasticity of the pelvic floor laboratory with a specific interest in anorectal func- puborectalis and may experience severe constipation as a result. tion. In addition to the balloon expulsion test, the evaluation generally involves manometry, including assessment of the MANAGEMENT reflexive relaxation of the internal sphincter after rectal disten- tion. The presence of this reflexive relaxation rules out Mild to Moderate Idiopathic Constipation Hirschsprung disease as a cause of constipation. In patients with Many cases of constipation can be managed with dietary and a nonrelaxing puborectalis, manometry during straining effort lifestyle changes, such as modifying the diet to include foods high demonstrates abnormal function of the external sphincter— in fiber and drinking adequate amounts of water. Physical inactiv- either failure to relax to enable expulsion or, on occasion, para- ity is associated with constipation, and encouraging moderate doxical contraction. Similar findings during straining can be exercise may lead to significant symptomatic relief. Fiber supple- documented by means of electromyography (EMG) with a mentation is a key component of therapy for mild constipation.8 sponge electrode in the anal canal. Fiber products (e.g., psyllium, methlycellulose, and polycarbophil) Defecography is commonly performed as well. Barium paste is increase stool bulk and stimulate colonic motility. Such products formulated so as to simulate a fecal bolus and placed in the rec- must be taken with sufficient amounts of fluid, or they may lead tum. The patient is asked to defecate on a radiolucent commode, to stool hardening. Often, patients have already tried fiber prod- and the event is recorded with fluoroscopy. During normal defe- ucts but did not achieve satisfactory results because the quantities cation, the puborectalis and the anal sphincter muscles relax, and were insufficient; daily doses as high as 20 g may be necessary for the rectum assumes a more vertical position with respect to the a therapeutic effect. Patients taking fiber products may experience anal canal, facilitating evacuation of stool [see Figure 3]. In a an increase in flatulence, particularly with fermentable fiber patient with a nonrelaxing puborectalis, defecography typically products. To improve tolerance, the amount of fiber should be demonstrates failure to open the anorectal angle and persistence increased gradually, and patients should be informed that the of the puborectalis impression during defecation, as well as failure effect of fiber may not be seen immediately. to empty completely.7 Other important findings that may be noted Nonlaxative therapy should be stressed; however, if dietary include rectocele, internal intussusception, and rectal prolapse. changes and fiber supplementation fail, judicious use of laxatives When appropriately selected, patients with obstructed defecation can bring about significant symptomatic relief. It should be kept resulting from such abnormalities may benefit from surgical cor- in mind that tachyphylaxis to laxatives is common and may lead to rection; however, even when these anatomic abnormalities are pre- chronic dependence. Stool softeners, or emollient laxatives (e.g., sent, they may not be the underlying cause of constipation. ducosate sodium and mineral oil), enhance penetration of water Interpretation of defecography is subjective, and there is wide nor- and fat into the stool, thereby making it less hard. These agents mal variation. Therefore, the diagnosis of a nonrelaxing puborec- may be of use on a relatively short-term basis. Ducosate sodium is talis should be based not on a single test result but, rather, on the less effective than fiber supplementation9; stool softeners should totality of the diagnostic findings. not be used as a substitute for fiber. The diagnosis of nonrelaxing puborectalis syndrome is made in Stimulant laxatives, including cascara, anthraquinones (senna persons with constipation in whom there is evidence of failure of and rhubarb), castor oil, and bisacodyl, are common components
  5. 5. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 5 of popular over-the-counter medications.These agents have direct employed in female patients who do not respond to conservative neuromuscular or mucosal effects, resulting in enhanced GI motil- measures. ity and altered mucosal transport (and thus increased intestinal secretion).8 Long-term use or abuse of anthraquinones can lead to Severe, Long-standing Constipation or Refractory Constipation melanosis (discoloration of the colonic mucosa caused by pigment Nonrelaxing puborectalis Patients with constipation arising deposition in colonic macrophages). from a nonrelaxing puborectalis often benefit from biofeedback.14 Osmotic laxatives contain compounds that either are not In this modality, a device (e.g., an anorectal manometer) is used to absorbed or are poorly absorbed. If the solutions are hypertonic, monitor pelvic floor activity; electrodes may also be used for EMG they cause water to move into the bowel lumen to maintain tonic- biofeedback. Patients observe pressure changes (or EMG activity) ity.10 Common preparations include magnesium and phosphate during attempts to evacuate. Through trial and error, they are salts. Ingestion of large amounts of such preparations can lead to taught to modify their responses until appropriate relaxation is hypermagnesemia or hyperphosphatemia, mainly in patients with achieved, the aim being to retrain the pelvic floor to relax during renal failure. The large fluid shifts that result when these com- defecation. Training may have to be reinforced at intervals. Accu- pounds are used for bowel preparation may be dangerous in rate determination of the success rate of biofeedback is difficult, patients with underlying heart disease. Polyethylene glycol (PEG) in that the published literature consists primarily of case series and is a high-molecular-weight compound that is not absorbed and most of the trials that have been conducted have not included a thus functions as an osmotic laxative. PEG preparations are com- placebo arm. It has been estimated that the success rate may be as monly administered as isotonic solutions and therefore cause only high as 70%; however, this estimate is probably overoptimistic.15 minimal fluid or electrolyte shifts when consumed rapidly (as in If biofeedback fails, injection of botulinum toxin into the pub- bowel preparation). PEG compounds are available as laxatives orectalis under ultrasonographic guidance may be attempted. To that can be taken either intermittently or regularly. date, published reports have evaluated this approach only in rela- Tegaserod, a 5-HT4 partial agonist, has been shown to alleviate tively small study groups; the results, though not decisive, are bloating and increase stool frequency by improving gut motility promising, in that the use of botulinum toxin clearly brought and decreasing visceral sensitivity.11 It may be prescribed for about noticeable improvements in manometric and defecograph- women with constipation-predominant irritable bowel syndrome ic findings16 and symptomatic improvements in the majority of (IBS) (see below) and for either male or female patients younger patients.17 Other experimental techniques available for treatment than 65 years who have idiopathic constipation. Tegaserod has of nonrelaxing puborectalis syndrome are electrogalvanic stimula- been associated with the development of diarrhea; typically, the tion18 and sacral nerve stimulation (SNS).19 Currently, surgical diarrhea resolves when the drug is discontinued, but occasionally, approaches do not play a role in the treatment of constipation sec- it is severe. In addition, several cases of ischemic colitis have been ondary to a nonrelaxing puborectalis. reported in patients receiving tegaserod. Although no causal rela- tion has been established, patients should be warned to cease tak- Slow-transit constipation Slow-transit constipation, also ing tegaserod and immediately contact their physician if abdomi- known as colonic inertia, is most common in young women and nal pain worsens. often starts at puberty. It is characterized by abnormally slow for- Enemas and suppositories act via a number of mechanisms, ward propulsion of colonic contents. The cause of slow-transit including softening of the stool, stimulation of rectal contraction constipation is unknown, though abnormalities in a number of by rectal distention, and direct alteration of mucosal secretion. cellular and neuromuscular modulators of GI motility have been They may be useful for occasional administration. found in patients with this condition.20,21 Although patients with idiopathic slow-transit constipation are frequently resistant to lax- Constipation-Predominant Irritable Bowel Syndrome ative therapy, many respond to osmotic PEG laxatives. Surgery In patients with constipation, significant abdominal pain, and no should be considered as an option only in the most severely affect- identifiable secondary cause of constipation, the diagnosis of con- ed patients, in whom aggressive laxative therapy has repeatedly stipation-predominant IBS may be appropriate [see Table 2].12,13 failed over a prolonged period. Even in specialized centers, only Often, patients with constipation-predominant IBS respond to about 5% of patients presenting with constipation are considered reassurance and fiber supplementation. Tegaserod may be appropriate candidates for surgical treatment.22 The operation most commonly performed to treat slow-transit constipation is subtotal colectomy with ileorectal anastomosis, performed via either an open or a laparoscopic approach. The Table 2—Rome II Criteria for Diagnosis colon is removed to the level of the sacral promontory in a stan- dard fashion; the ileorectal anastomosis may be either stapled or of Constipation-Predominant Irritable handsewn. Constipation is less likely to recur with this anastomo- Bowel Syndrome8 sis than with an ileosigmoid anastomosis.23 At least 12 wk of abdominal pain or discomfort in the past year, with at Surgical therapy is generally successful in improving bowel func- least 2 of the following: tion: in most patients, stool frequency rises to one to three bowel 1. Relief with defecation movements a day. Unfortunately, surgery may not satisfactorily 2. Onset associated with a change in frequency of stool alleviate other symptoms (e.g., abdominal discomfort or bloat- 3. Onset associated with a change in form (appearance) of stool ing),24 and patients should be made aware of this possibility before operation.The key to successful surgical treatment is patient selec- Supportive symptoms of constipation-predominant IBS: 1. Abnormal stool frequency (< 3 bowel movements/wk) tion. Overall, the majority of well-selected patients are satisfied 2. Abnormal stool form (hard or lumpy stools) with the results of surgical treatment25,26; however, long-term post- 3. Abnormal stool passage (straining during bowel movement, feeling operative complications, particularly small bowel obstruction, are of incomplete evacuation) common. In addition, patients may manifest symptoms of a more global GI dysmotility disorder in the long term.
  6. 6. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 6 but its main impact is on quality of life. Affected patients experi- ence embarrassment and shame, and many dramatically alter their lifestyle in an effort to avoid accidents. Normal continence depends on a chain of interdependent processes, and disruption of any of the links in the chain can lead to incontinence. Frequently, a combination of factors is responsi- ble for the incontinence. To care about continence, persons must have adequate mental function, and to maintain normal continence, they must have an intact neurologic arc from the brain to the anal sphincter. A wide array of neurologic disorders can lead to incontinence, including dementia, strokes, spinal cord injury, multiple sclerosis, and dia- betic autonomic neuropathy. So-called idiopathic fecal inconti- nence is caused by pelvic floor denervation resulting from traction injury to the pudendal nerves.30 The injury is usually caused by straining and consequent pelvic floor descent during obstetrical delivery or by chronic straining at stool. Conditions characterized by abnormal GI function, especially diarrheal states, can cause or exacerbate incontinence. Common causative conditions include infectious diarrhea and inflammatory bowel disease. Diarrhea-predominant IBS can contribute to incon- tinence in patients with other associated disorders. Fecal impaction Figure 4 Shown is an obstetric sphincter is an important cause of incontinence, particularly in older and injury. institutionalized populations.31 Abnormalities of the pelvic floor are frequent causes of inconti- Other surgical approaches sometimes employed in this setting nence. Some such abnormalities are congenital malformations are ileostomy [see 5:30 Intestinal Stomas], total proctocolectomy (e.g., imperforate anus, rectal agenesis, and cloacal defect). More with ileal pouch–anal anastomosis (IPAA) [see 5:33 Procedures for often, abnormalities are attributable to acquired sphincter injuries. Ulcerative Colitis], segmental colectomy [see 5:34 Segmental Common causes of sphincter injury include obstetric injury, pelvic Colon Resection], and colectomy with cecorectal anastomosis; how- fracture, and traumatic impalement [see Figure 4]. One of the most ever, data on the long-term effectiveness of these approaches in requent causes is an anorectal procedure, such as fistulotomy,32 large numbers of patients are lacking. Completion proctectomy sphincterotomy,33 or anal dilatation.34 Sphincter-sparing rectal with IPAA and ileostomy are options for patients who remain resections can also lead to incontinence as a consequence of both severely symptomatic after ileorectal anastomosis but who manifest the loss of the normal rectal reservoir and the sphincter injury no evidence of proximal dysmotility. caused by transanal introduction of intraluminal staplers. Not infrequently, patients have both slow-transit constipation and a nonrelaxing puborectalis. In such cases, it is essential that CLINICAL EVALUATION the obstructed defecation be addressed before any surgical treat- ment is carried out. Even after biofeedback, if surgical therapy is History attempted in this setting, as many as 50% of patients will be dis- A careful patient history and a directed physical examination satisfied with the results.27 are the most important elements of clinical evaluation for a patient with fecal incontinence [see Figure 5].The patient should be asked Severe idiopathic constipation Patients who have severe about the onset and nature of the incontinence (e.g., whether the constipation but show no signs of slow-transit constipation, pelvic floor dysfunction, or IBS should be treated with reassurance and stool is liquid or solid and whether flatus is present), any associat- symptomatic management. Osmotic laxatives—in particular, PEG ed changes in stool consistency or bowel habits, and the frequen- products—may be very useful in this group. Operative treatment cy of incontinence. A pertinent but thorough medical, surgical, plays no role in management; however, experimental approaches and obstetric history should be obtained, and any underlying con- (e.g., SNS) are being evaluated for possible use in this setting. tributory conditions (e.g., colitis) should be treated.The impact of the incontinence on the patient’s quality of life should be assessed, at least qualitatively. Fecal Incontinence Physical Examination Fecal incontinence may be defined as the involuntary loss of rectal contents through the anal canal. It is a relatively common Physical examination should focus primarily on the perineum. condition, occurring in an estimated 2.2% of persons in the Seepage and secondary perineal skin breakdown should be noted, United States.28 Its exact prevalence is unknown, however, and as should scars from previous surgical treatment or trauma. appears to vary with the population being studied. For example, Perineal body deformity is an important sign of obstetric injury, nearly 50% of nursing home patients are incontinent to stool.28 and gaping of the anus with traction on the buttocks is suggestive Fecal incontinence is often treated inadequately, either because of of rectal prolapse.When prolapse is suspected but not evident, the underreporting of symptoms to the physician29 or because of igno- patient should be asked to strain while seated on a commode. rance or disinterest on the physician’s part. Digital rectal examination is useful for detecting low rectal tumors Fecal incontinence makes a significant contribution to med- and fecal impaction; it also provides a qualitative assessment of ical morbidity (e.g., urinary tract infections and decubitus ulcers), both resting sphincter tone and voluntary squeeze pressure.
  7. 7. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 7 Patient presents with fecal incontinence Evaluate patient. History: Determine onset, nature, and frequency of incontinence. Obtain thorough medical, surgical, and obstetric history. Physical examination: Focus particularly on perineum. Perform digital rectal examination. Perform endoscopy to exclude neoplasm or inflammation. Patient has diarrhea Patient does not have diarrhea Assess and treat cause of diarrhea (colitis, hypersecretory tumor, radiation exposure, overflow). Provide medical treatment (fiber, dietary changes, Perform anorectal physiology testing: barrier cream, antidiarrheal agents, bowel regimen). • Anorectal manometry • EAUS • Defecography (optional) Diarrhea resolves Diarrhea does not resolve Patient has major sphincter defect Patient has minor sphincter defect or no defect at all Perform overlapping sphincteroplasty. Administer biofeedback. Incontinence is Incontinence persists mitigated or resolves Perform EAUS. Incontinence Incontinence is persists mitigated or resolves Persistent sphincter defect No persistent sphincter defect is identified is identified Repeat sphincteroplasty, with or without biofeedback. Consider other surgical options, taking into account age, comorbid conditions, and technical issues: • Dynamic graciloplasty, artificial anal sphincter, or Incontinence is Incontinence persists sacral nerve stimulation mitigated or resolves • Colostomy Figure 5 Algorithm outlines workup and management of fecal incontinence. INVESTIGATIVE STUDIES respectively. EMG may be used to diagnose neuropathic injury of Endoscopy should be performed on all incontinent patients to the pelvic floor. Although concentric-needle EMG is the most exclude a neoplastic or inflammatory condition. In most cases, accurate technique, most centers employ a glove-mounted intra- flexible sigmoidoscopy is adequate, but if the patient has unex- anal electrode to measure pudendal nerve conduction time (i.e., plained diarrhea, bleeding, or changed bowel habits, complete pudendal nerve terminal motor latency [PNTML]).The practical colonoscopy should be performed. utility of PNTML testing is debatable, however, and opinions vary Anorectal testing is indicated for most patients with significant regarding the test’s ability to predict successful outcomes after anal incontinence, particularly if operative treatment is being consid- sphincter repair.36,37 When the cause of incontinence is uncertain, ered. The most important test is endoanal ultrasonography dynamic imaging of the pelvic floor with defecography or MRI (EAUS), which yields a highly accurate assessment of sphincter may reveal an occult pathologic state (e.g., occult rectal prolapse). integrity [see Figure 6].35 At some centers, magnetic resonance MANAGEMENT imaging has become the test of choice for evaluating the pelvic floor. Anal manometry provides a quantitative assessment of rest- ing and squeeze anal pressures, which serve as indicators of inter- Conservative Management nal anal sphincter function and external anal sphincter function, Minor incontinence should be treated first with conservative mea-
  8. 8. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 8 sures. Dietary changes (e.g., avoidance of foods that cause diarrhea to work medially toward the attenuated tissue in the midline. or urgency), fiber supplementation, and bowel habit training are Lateral dissection is extended back on either side until enough helpful for most patients, as is regular use of loperamide. Perianal healthy muscle is mobilized to allow overlapping without tension. skin excoriation should be treated with a barrier cream, and seepage Generally, however, lateral dissection should not extend beyond may be controlled either with placement of a small cotton wick at the the midcoronal line, so as not to risk injury to the inferior rectal anal orifice or, occasionally, with rectal washouts. branches of the pudendal nerves, which cross the ischiorectal fos- sae posterolaterally. Dissection is then carried out cranially in the Biofeedback rectovaginal septum to the level of the puborectalis. The muscle is Biofeedback appears to be an effective therapy for fecal inconti- divided through its midline scar, but the scar is preserved to help nence in a high percentage of patients.38,39 It is an inherently attrac- prevent the sutures from tearing through. tive approach because it is simple, painless, and risk-free. However, the biofeedback literature consists mostly of small, uncontrolled, Step 3: overlapping repair. The tapes on the buttocks are then re- retrospective studies; a randomized, controlled trial from 2003 leased, and an overlapping sphincter repair is performed with ab- found that biofeedback had no advantages over standardized med- sorbable mattress sutures [see Figures 7b, c]. A snug plication is univer- ical and nursing care (i.e., advice) or advice plus sphincter exercises.40 sally advocated, but unfortunately, there are no generally accepted objective criteria to define exactly what “snug” means in this context. Sphincteroplasty Many authorities advise plication of the puborectalis (so-called lev- Anal sphincter repair is the most widely accepted operation for atorplasty) at the cranial aspect of the repair to maximize the length fecal incontinence [see Figure 7]. In acute situations (e.g., when an of the anal canal.42 Others favor individual dissection and repair of obstetric sphincter injury is recognized), immediate direct repair is the internal and external sphincter muscles, but at present, there is generally recommended. Unfortunately, as many as 75% of no compelling evidence for the superiority of this approach. women have persistent external anal sphincter defects after prima- ry repair, and about 60% have some degree of incontinence.41 If Step 4: restoration of perineal body. The skin incision is closed in a immediate repair is not attempted, surgical treatment should be V-Y configuration [see 3:7 Surface Reconstruction Procedures] to delayed at least 3 to 6 months to permit resolution of local tissue restore the perineal body and maximize the distance between the inflammation and edema. anus and the vaginal introitus. The wound is left partially open or For incontinent patients with established sphincter defects, closed loosely over small Penrose drains to minimize the risk of overlapping sphincteroplasty is the procedure of choice. Complete surgical site infection [see Figure 7d]. A diverting stoma is not gen- bowel preparation is carried out before the procedure, and pro- erally indicated but may be considered in special situations (e.g., phylactic antibiotics are administered. multiple previous failed repairs, Crohn disease, or various chronic diarrheal states). Operative technique Step 1: initial dissection. The patient is placed in the prone jackknife position, with the buttocks taped Outcome evaluation Overlapping sphincteroplasty yields sub- apart and a large roll beneath the hips. A curvilinear incision is stantial clinical improvement in approximately 65% to 80% of made over the perineal body, and the anoderm and the anal canal patients.43,44 Unfortunately, current data indicate that results deteri- mucosa are raised as an endodermal flap [see Figure 7a].The vagi- orate significantly over time.45-47 When sphincteroplasty fails, repeat nal wall is mobilized anteriorly. EAUS evaluation should be done to confirm that the muscle wrap is intact, and another repair should be performed after 6 to 12 months Step 2: mobilization of sphincter muscle. It is often easiest first to if a significant defect persists.48 If the muscle wrap is intact, the func- identify normal muscle laterally in the ischiorectal fossa and then tional outcome can often be improved by means of biofeedback.49 a b Figure 6 Endoanal ultrasonograms show (a) a normal anal sphincter and (b) a sphincter defect.
  9. 9. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 9 a b c d Figure 7 Sphincteroplasty. (a) With the patient in the prone jackknife position, a curvilinear incision is made. Inferior rectal nerves cross the ischiorectal fossa posterolaterally. (b) Anterior levatorplasty is performed, and overlapping sphincter repair is then initiated. (c) Sphincter repair is completed. (d) The incision is closed, with drains in place (optional), and V-Y plasty is done to restore the perineal body. Nonstimulated Muscle Transposition Various surgical options are available for patients in whom sphincteroplasty has failed or who are not candidates for the pro- Attempts to restore continence by creating a neosphincter from cedure (e.g., those with pudendal neuropathy and an anatomical- transposed skeletal muscle date back to the early 20th century. ly intact sphincter). A number of these options are investigational, Most such attempts have made use of either the gluteus max- and further study is needed to determine their eventual role (if imus54 or the gracilis.55 Good results have frequently been report- any) in incontinence therapy. ed, but many authorities believe that the quality of the resulting continence is poor. One of the main limitations of nonstimulated Postanal Repair muscle transposition is that patients are typically unable to main- Sir Alan Parks devised the postanal repair in 1975 to treat tain voluntary contraction of the transposed muscle over the long patients with incontinence and intact sphincters.The initial results term. were encouraging but tended to deteriorate over time. Consequently, despite evidence of lasting improvement in some Stimulated (Dynamic) Graciloplasty patients, this operation is rarely performed today.50,51 Successful electrical stimulation of a transposed gracilis by means of an implantable pulse generator was first reported in Injectable Biomaterials 1988.56 Such stimulation has two main effects. First, it converts the A number of studies have explored the use of injectable biomate- fast-twitch, rapidly fatigable gracilis to a slow-twitch, fatigue-resis- rials to provide bulk around the anal sphincter and thereby improve tant muscle that is capable of tonic contraction for prolonged peri- continence. The materials employed have included autologous fat, ods.57 Second, electrical stimulation maintains tonic muscle con- cross-linked collagen, silicone, and carbon-coated beads.52,53 Several traction without the need for continuous voluntary control on the small, uncontrolled studies have reported promising results, but part of the patient. A small number of centers with particular larger series with longer follow-up times are needed. expertise in dynamic graciloplasty and high patient volumes have
  10. 10. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 10 reported good results with acceptable morbidities58; however, three by means of bony landmarks; S3 is typically about 1.5 cm off the large multicenter trials have reported less encouraging results with midline at the level of the sciatic notch.65 Initial testing is per- prohibitive morbidities.59-61 In the United States, dynamic gracilo- formed with an insulated spinal needle and an external pulse gen- plasty is not available, because it has not been approved by the erator. Stimulation of each foramen leads to a typical response: S3 Food and Drug Administration. Elsewhere in the world, the oper- causes a bellows-type contraction of the pelvic floor and dorsiflex- ation can be considered a salvage option at centers with the requi- ion of the ipsilateral great toe. Usually, several levels are tested site expertise and experience. until the optimal site is identified. A temporary pacing wire or a permanent quadripolar lead is then inserted and connected to an Artificial Anal Sphincter external stimulator [see Figure 9]. The artificial anal sphincter is an implantable system consisting Patients are asked to provide a baseline continence diary, and a of three parts: an inflatable perianal cuff, a pressure-regulating bal- second diary is recorded during the test stimulation period. If con- loon, and a control pump that is implanted in the scrotum or the tinence is significantly improved (e.g., by 50% or more), the sec- labia majora [see Figure 8]. Good results have been reported in ond stage of SNS, implantation of a permanent lead (if not already individual case series,62 but device infection has been a prob- in place) and a pulse generator, is carried out.This second stage is lem.63,64 In a large multicenter trial, 46% of patients required sur- also performed with the patient prone, under local anesthesia, and gical revision of the device, including 25% who required revision sedated.The pulse generator is implanted in a subcutaneous pock- or explantation because of infection. Of the patients who under- et on the same side as the stimulating electrode. went implantation, 53% had successful results; among those with Both stages of SNS are performed as outpatient procedures. a functioning device in place, the success rate was 85%. The pulse generator is activated and its stimulation parameters set by means of a telemetric programmer. If problems (e.g., Sacral Nerve Stimulation pain) develop or if the results of stimulation are inadequate, In SNS, an electrode is inserted through a sacral foramen and the system can be reprogrammed in a variety of ways: stimula- used to stimulate the sacral nerves. To date, the procedure has tion frequency can be altered, voltage can be increased or de- been employed mainly in patients with intact anal sphincters creased, and the configuration of the stimulating electrodes can (including those with intact repairs). It is available for treatment of be modified. fecal incontinence in Europe but has not yet received FDA SNS has been shown to be a highly effective treatment for fecal approval for this indication in the United States. incontinence.66-68 Unlike dynamic graciloplasty and the artificial SNS is generally carried out in two stages. The first stage, anal sphincter, SNS is associated with only minimal morbidity. In peripheral nerve evaluation (PNE), is performed to confirm a a multicenter prospective trial, the frequency of incontinent events muscular response to stimulation of the sacral nerves, to identify dropped from 16.4/wk at baseline to 3.1/wk at 12 months after the optimal site for stimulation (S2, S3, or S4) and to determine SNS and 2.0/wk at 24 months. Fecal incontinence–related quali- the clinical response to stimulation with an external pulse genera- ty of life was significantly improved. tor. In most cases, stimulation of the S3 nerves provides the opti- Because of its high success rate and excellent safety profile, mal response. many authorities now consider SNS the salvage procedure of PNE is performed with the patient prone and under local anes- choice for patients with refractory incontinence. If SNS fails, more thesia, with or without sedation. The sacral foramina are located aggressive treatments may still be tried at a later time. a b Figure 8 Artificial anal sphincter. (a) A three-part implantable system is used (shown is Acticon; American Medical Systems, Minneapolis, Minnesota). (b) Depicted is the recommended placement of the artificial sphincter device in the patient.
  11. 11. © 2005 WebMD, Inc. All rights reserved. ACS Surgery: Principles and Practice 5 Gastrointestinal Tract and Abdomen 16 Motility Disorders — 11 a b c Figure 9 Sacral nerve stimulation. (a) A lead containing four electrodes is used for SNS. (b) The sacral foramina are identified; in most cases, S3 is the optimal choice for stimulation. (c) Shown is the quadripolar lead in position. Colostomy patient satisfaction and marked improvements in subjective quali- Although creation of a colostomy does not restore continence, it ty of life.69 In most cases, a simple end sigmoid colostomy with a does provide a degree of bowel control in a manner that allows Hartmann pouch is the appropriate procedure, and it can often be patients to resume their normal activities without fear of accidents. performed with relatively little operative trauma by using a laparo- Surprisingly few data are available regarding colostomy for incon- scopic or minilaparotomy technique. Patients should receive pre- tinence; however, one questionnaire study of patients who under- operative counseling from an enterostomal therapist, and the opti- went colostomy for incontinence reported extremely high levels of mal stoma site should be marked before the procedure is initiated. References 1. Walter S, Hallbook O, Gotthard R, et al: A popu- 5. Minguez M, Herreros B, Sanchiz V, et al: Pre- is superior to docusate sodium for treatment of lation-based study on bowel habits in a Swedish dictive value of the balloon expulsion test for ex- chronic constipation. Aliment Pharmacol Ther community: prevalence of faecal incontinence and cluding the diagnosis of pelvic floor dyssynergia in 12:491, 1998 constipation. Scand J Gastroenterol 37:911, 2002 constipation. Gastroenterology 126:57, 2004 10. DiPalma JA: Current treatment options for chron- 6. Glia A, Lindberg G, Nilsson LH, et al: Consti- ic constipation. Rev Gastroenterol Disord 4(suppl 2. Talley NJ: Definitions, epidemiology, and impact pation assessed on the basis of colorectal physiol- 2):S34, 2004 of chronic constipation. Rev Gastroenterol Disord 4(suppl 2):S3, 2004 ogy. Scand J Gastroenterol 33:1273, 1998 11. Muller-Lissner SA, Fumagalli I, Bardhan KD, et 7. Jorge JM, Habr-Gama A, Wexner SD: Clinical al: Tegaserod, a 5-HT(4) receptor partial agonist, 3. Klaschik E, Nauck F, Ostgathe C: Constipation— relieves symptoms in irritable bowel syndrome modern laxative therapy. Support Care Cancer applications and techniques of cinedefecography. patients with abdominal pain, bloating and consti- 11:679, 2003 Am J Surg 182:93, 2001 pation. Aliment Pharmacol Ther 15:1655, 2001 4. Prather CM: Subtypes of constipation: sorting out 8. Schiller LR: The therapy of constipation. Aliment 12. Lacy BE: Irritable bowel syndrome: a primer on the confusion. Rev Gastroenterol Disord 4(suppl Pharmacol Ther 15:749, 2001 management. Rev Gastroenterol Disord 3(suppl 2):S11, 2004 9. McRorie JW, Daggy BP, Morel JG, et al: Psyllium 3):S32, 2003
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Kumar D, Benson MJ, Bland JE: Glutaraldehyde Figures 2, 3, 7, 8, and 9 Alice Y. Chen.