Pediatric Colonic Motility Disorders 

Updated: Oct 18, 2018
Author: Nelson G Rosen, MD, FACS, FAAP; Chief Editor: Harsh Grewal, MD, FACS, FAAP 

Overview

Background

Everything about pediatric colonic motility disorders remains controversial. The medical community that treats colorectal problems in adults espouses many concepts and methods that have not been completely validated, such as artificial sphincters, cinedefecography, anorectal manometry, and biofeedback. The community that treats pediatric patients remains divided about intestinal neuronal dysplasia (IND), ultrashort Hirschsprung disease, and achalasia of the sphincter (see below).

It is to be hoped that future work will further define the spectrum of motility disorders of the bowel in children. This knowledge may lead to better-targeted therapies or more focused surgical approaches.

Motility in normal bowel function

Normal bowel function is the end result of a complex interaction of systems, many of which are still poorly understood. Fecal continence may be defined as the ability to remain clean, with no leakage of stool, between voluntary bowel movements.[1] To achieve this requires a balance of sensation, sphincteric control, and motility.[2]

The term motility refers to the peristaltic motion of the intestine. The colon receives liquid stool from the small intestine and slowly transports it to the rectum. During this journey, which usually takes 24 hours, water is absorbed from the liquid stool, and a semisolid product is presented to the rectum.

Colonic motions include various nonpropulsive contractions, as well as propulsive and mass peristalsis. Propulsive peristalsis consists of slow, irregular contractions that proceed in a craniocaudal direction. Mass peristalsis occurs several times daily and consists of a large peristaltic wave that moves contents toward the rectosigmoid. This peristalsis is suspected to be predominantly related to the gastrocolic reflex (ie, colonic contraction) stimulated by food passing out of the stomach into the small intestine.

Rectal motility differs from colonic motility in that it remains stationary and allows the stool to remain there until a socially acceptable time, when a massive contraction (mass peristalsis) pushes the stool out and completely empties the rectum.

Most patients with colorectal motility disorders have a system that moves too slowly and fails to empty completely. In the pediatric population, rapid colonic transit is usually unrelated to an inherent dysmotility. Instead, it is often related to short colonic length (either congenital or after surgery) or to an intra-abdominal inflammatory process, such as appendicitis with rupture or inflammatory bowel disease.

If the colon moves too slowly, stool accumulates and becomes hard and difficult to eliminate. This situation leads to fecal impaction. Eventually, liquid stool above the impaction leaks around the stool ball, and the patient seems incontinent. This is actually a pseudoincontinence referred to as encopresis.

Conditions affecting colonic motility

Many conditions affect colonic motility. Some babies are born with Hirschsprung disease, which is characterized by the absence of relaxatory ganglion cells in the distalmost colon. This problem is correctible with surgery, but children can still have constipation after the surgery.

Constipation is defined as difficult, incomplete, or infrequent evacuation of stool. The stool may be hard, but this feature is not essential. Idiopathic constipation is defined as constipation occurring in patients who do not have a clearly defined histologic defect in a portion of their colon. For example, children who are born with no evidence of Hirschsprung disease but still have severe constipation are considered to have idiopathic constipation.

Several subsets of idiopathic constipation are described. Patients with an essentially normal biopsy result who lack an anorectal inhibitory reflex on manometry may be said to have ultrashort Hirschsprung disease.[3] This disease entity and its treatment remain controversial. Differentiating this disease from another equally controversial entity, referred to as achalasia of the anal sphincter, is difficult.

IND is another controversial disorder.[4] Meier-Ruge originally described this condition in 1971, and it most likely represents a spectrum of neural-crest malformations rather than a distinct disorder. Both its diagnosis and its treatment remain controversial.

Some patients have hypoganglionosis on biopsy. No definite criteria for hypoganglionosis have been established, and the finding may simply represent the result of chronic colonic dilatation secondary to stool retention. The ganglion cells may appear to be fewer than normal because they are spaced far apart.

Anatomy

Innervation of the normal colon is derived from the autonomic nervous system and involves the following three distinct plexuses:

  • Auerbach plexus, located between the inner circular and outer longitudinal smooth muscle layers
  • Henle plexus, located at the inner margin of the circular muscularis propria
  • Meissner plexus, located beneath the muscularis propria

These plexuses are present throughout the colon and terminate above the level of the dentate line. The level at which they terminate varies considerably; however, the presence of a normal aganglionic zone above the dentate line that extends cranially for a short distance and varies with age and size is a generally accepted indicator. When a patient is being evaluated for Hirschsprung disease, a biopsy sample must be obtained above this normal aganglionic zone.

Pathophysiology

Children with idiopathic constipation have intestinal hypomotility. Their colons move more slowly than normal, and their rectums may incompletely evacuate without assistance. This leads to stool remaining in the colon for several days, during which time it dries out, resulting in large, hard stools. The colon eventually becomes dilated to accommodate this enlarged quantity of stool. As the bowel dilates, its hypomotility worsens, exacerbating the original problem. Fecal impaction eventually occurs.

Trying to pass large hard stools can be painful. It can even cause an anal tear or fissure, which is exquisitely painful and may instill in the child the desire to avoid having a bowel movement. This is the beginning of stool-holding behavior, which can be difficult to break.

Etiology

The etiology of idiopathic colonic dysmotility remains unclear. Inadequate water intake is not the cause of constipation for otherwise healthy children.

Many physicians believe that children most commonly retain stool for psychological reasons. Although some children who have severe constipation eventually develop a psychological component to their disorder, this is usually secondary. Primary stool retention is rare and often follows a discernible traumatic event, such as a painfully hard stool with a resulting fissure.

Some have implicated incomplete relaxation of the anal sphincter as the primary causative factor; however, this theory does not adequately explain these conditions.

Although a definite etiology is unknown, various abnormalities have been identified in children who have slow-transit constipation. However, it is not clear precisely how these findings relate to the symptomatic intestinal dysmotility. Abnormalities observed in children with slow-transit constipation include the following:

  • Decreased quantity of substance P in intestinal nerve fibers
  • Decreased number of interstitial cells of Cajal
  • Decreased number of ganglion cells (hypoganglionosis)
  • Abnormalities in colonic monoclonal antineurofilament antibodies
  • Decreased plasma levels of motilin
  • Increased plasma levels of pancreatic polypeptide

Epidemiology

Idiopathic constipation is the most common intestinal dysmotility disorder in children, but its true incidence is unknown. Although constipation affects more women than men, it affects more boys than girls.

Hirschsprung disease occurs in roughly 1 in 5000 children, with a male preponderance for the most common (short segment) form of the disease.

Prognosis

If colonic motility problems are aggressively treated, the outcome for most children is excellent. The overwhelming majority can become clean with a laxative regimen. Children whose conditions are unmanageable with laxatives may do well on enema regimens or may benefit from surgical treatment if they have isolated megasigmoid or megarectum. Children rarely have conditions so refractory to medical management that they require a diverting ostomy. Such cases are usually referred to as intestinal pseudo-obstruction, which is essentially a diagnosis of exclusion.

Most parents wish to know if their child will require laxatives or enemas for life. This question is difficult to answer; however, unless something changes in the colon, the answer is “perhaps.”

Some patients do require laxatives or enemas for life. Others can often avoid the need for traditional medication laxatives by increasing their ingestion of laxative foods and soluble fiber. Children tend to be finicky eaters and typically do not do well with such dietary restrictions. When they are old enough to understand the importance of laxative foods and fiber, they can often cut down or even eliminate their use of additional laxatives. This occurs only with older children or young adults who become self-motivated.

Parental desire alone is rarely effective in making a willful child become compliant. The final answer to the question posed above will not be clear until the child has become an adult and is ready to assume responsibility for his or her own care and quality of life.

 

Presentation

History

A complete birth history must be obtained, including first passage of meconium. Failure to pass meconium in the first 24-36 hours is associated with Hirschsprung disease. Any history of constipation from birth and multiple bouts of enteritis with diarrhea and distention suggests undiagnosed Hirschsprung disease. All children with such findings need both contrast enema and biopsy.

A history of meconium plug, constipation, and recurrent pulmonary issues suggests cystic fibrosis and necessitates performance of a sweat test. All children who present with rectal prolapse require sweat testing.

Children with idiopathic constipation often present with abdominal pain and distention. When the pain is in the right lower quadrant, their condition may be mistaken for appendicitis but can usually be distinguished from appendicitis on the basis of chronic issues such as delayed passage of stool and, perhaps, soiling. Such children have probably been examined by several physicians for the problem and may have been referred to a psychologist for stool-holding behavior.

Many children present with fecal impaction with or without soiling. Fecal incontinence is a common presenting complaint.

Pertinent questions in the history include ”How often does the child stool?” and ”What is the character of the stool?” Determining if the child is still wearing diapers because of accidents is important; if the child is not still wearing diapers, determining how often the child stains the underwear or has accidents is important. By the time children present to a surgeon's office, they have usually tried most commercially available laxatives and enemas, and their parents are frustrated.

Physical Examination

Comprehensive physical examination must be done to exclude a systemic illness manifesting with ileus or other nonidiopathic causes of constipation. In otherwise healthy children with normal physical findings, the abdominal examination is the most pertinent study. The abdomen may be distended or tympanitic but is rarely tender. If the child is put at ease and if he or she can be examined well, firm stool may be palpable in the left side of the abdomen.

Rectal examination should be reserved for the end of the consultation because it often renders the child uncooperative. The rectal examination usually reveals the child's present state of cleanliness, which allows the examiner to put the presenting complaints into perspective. Look for any anatomic abnormalities, such as trauma, skin tags, fissures, fistulas, perirectal abscesses, polyps, or rashes.

Small babies may not be able to undergo digital rectal examination, and their anus should be sized with a Hegar dilator to rule out congenital stenosis. In full-term babies, the average anal diameter is 12 mm.

 

Workup

Laboratory Studies

Currently, no blood tests are specifically useful in the diagnosis and treatment of pediatric colonic motility disorders. If a patient presents with distention and abdominal pain and has gone several days without a bowel movement, a complete blood count (CBC) should be obtained. The presence of leukocytosis suggests an acute etiology (eg, appendicitis or ovarian cyst rupture) rather than chronic constipation.

Imaging Studies

All patients should undergo baseline posteroanterior (PA) and lateral sacral radiography to ensure that they do not have sacral malformations, which could suggest spinal dysraphism or a presacral mass as the underlying cause. Children with an abnormal sacrum should undergo spinal ultrasonography (US) if they present before age 6 months or should undergo magnetic resonance imaging (MRI) if they present after age 6 months. Abdominal radiography and contrast enema study are the main diagnostic modalities.

A single-view flat abdominal image is the most useful image in the workup of patients with a colonic motility disorder. Retained stool in the rectum, the sigmoid, and the left side of the colon is a pertinent finding. Stool in the right side of the colon is meant to be passed the next day; therefore, this finding is irrelevant. However, persistent left-side stool is a sign of incomplete emptying.

Radiographic findings should be considered in the context of when the image was obtained. If the image was obtained many hours after the patient's last bowel movement, the appearance of stool almost ready to come out is expected. If the image was obtained not long after a bowel movement, this finding represents incomplete evacuation.

Contrast enema is an extremely important examination and should be performed in all children who have problems with colonic motility to assess the size of the colon, to see if any segments are dilated, and thus to determine if hypomotility is present.

If the patient is a newborn and the diagnosis in question is Hirschsprung disease, a contrast enema study is classically performed with barium. In children with suspected meconium ileus or a meconium plug or in older children with constipation, it should always be performed with water-soluble contrast material. Water-soluble contrast material draws water into the stool and helps clean out the impacted stool. Despite this effect, the contrast agent may not be cleared for days; if the contrast agent persists for days, it is a sure sign of severe constipation.

Many gastroenterologists perform transit studies, in which patients ingest radiopaque markers that are then followed through the intestinal tract by means of radiography. These studies may be useful in determining where the markers accumulate over time and whether any segments of the colon exhibit hypomotility.

Cinedefecography involves a real-time movie taken of the patient during the act of defecating a thick barium paste. The anorectal angle is determined, and the motion of all of the pelvic musculature is examined. This study is rarely performed in children, and its findings do not help in targeting specific therapies.

Manometry

Anorectal manometry, which in this context requires special equipment and personnel with expertise in children, consists of inserting a catheter with attached pressure sensors into the anus and then assessing anal function by measuring the pressures generated during squeezing and passive stretching. The rectoanal inhibitory reflex is seen when the internal anal sphincter relaxes during passive distention produced by inflating a balloon in the rectum. This reflex is classically absent in Hirschsprung disease.

Clinicians at centers with extensive expertise in anorectal manometry often use this test for first-line screening in infants and children after the neonatal period.[5] Although this test may be helpful in some settings, it is of limited use in evaluating idiopathic constipation. Results of anorectal manometry alone are insufficient as the only indication for surgical treatment of Hirschsprung disease.

Total colonic manometry is similar to anorectal manometry but is used to measure pressures throughout the entire colon by means of a long catheter, which is placed during endoscopy and with the child under sedation.[6, 7, 5] This procedure may be useful when colonic dysmotility is severe and when the diagnosis of pseudo-obstruction is in question. Total colonic manometry is performed in few centers and has yet to become a mainstream study.

There is growing interest in high-resolution colonic and anorectal manometry to assess motility. However, few studies of this approach have been done in children, and it is not yet clear whether it affords any significant advantage over conventional manometry in this setting.[8]

Histologic Findings

Histologically, Hirschsprung disease is characterized by the absence of ganglion cells, nerve-bundle hypertrophy, and increased acetylcholinesterase staining.

In patients with idiopathic constipation, biopsy sample findings are normal when conventional histologic techniques are used. Experimental advanced techniques (C-Kit staining and electron microscopy) have been able to demonstrate a deficiency of the interstitial cells of Cajal, which seem to play a vital role as pacemakers of intestinal motility.

Intestinal neuronal dysplasia (IND) is a nebulous condition. Histologic criteria vary. Patients may have giant cells, nerve plexus hyperplasia, increased acetylcholinesterase staining, and various other findings. Special staining techniques may be required to demonstrate these abnormalities. Not all patients with these conditions have all of the findings. This disease entity remains highly controversial.

 

Treatment

Approach Considerations

Surgery is indicated only for the treatment of non-Hirschsprung colonic motility disorders when conventional therapies have failed. Most patients who present to a surgeon with a motility disorder are already thought to have a condition refractory to laxative or enema administration. The clinician should personally direct an aggressive course of nonoperative treatment before considering a surgical option.

If Hirschsprung disease cannot be completely excluded on the basis of the patient's history and imaging studies, suction or full-thickness rectal biopsy must be performed. For all other children whose condition proves refractory to laxatives, contrast enema is then performed to determine if any segments of the colon are dilated.

Children with a normal-caliber colon or total colonic dilatation usually do not do well with surgical resection. If their condition proves refractory to laxatives, it should be treated with daily enemas. If they do well with a rectal enema regimen, a continent appendicostomy (Malone procedure) may be fashioned as a conduit to ease enema administration and to increase the child's independence. Some clinicians use percutaneously placed cecostomy buttons for the same purpose.

Children with conditions refractory to laxatives and isolated rectosigmoid dilatation on contrast enema may benefit from sigmoid resection and primary anastomosis.

Surgical indications for intestinal neuronal dysplasia (IND) remain unclear. Currently, further study is required to clarify the role, if any, of surgery. Surgical indications for ultrashort Hirschsprung disease or sphincter achalasia are also controversial. Some surgeons advocate myectomy or injections of botulinum toxin, though results vary widely.

Children who have Hirschsprung disease should undergo surgical treatment for that condition. The aganglionic colonic segment is excised, and the ganglionated bowel is brought down to the anus. Several procedures are described for this condition, with no single procedure demonstrating clear advantages or disadvantages in terms of outcome.

For children with idiopathic constipation, sigmoid colectomy is contraindicated if no segmental dilatation is demonstrable on contrast enema study.

Button cecostomy or Malone appendicostomy is contraindicated if a child's condition is not yet well managed with an enema regimen. These procedures change the route of enema administration but do not improve the efficacy of an enema. If the enema regimen has not been fine-tuned from the rectal route, adding a Malone or a cecostomy button does not improve the condition.

Nonoperative Therapy

Medical therapy is relevant only for idiopathic constipation. Two types of medical treatments are considered: laxatives and enemas.

Patients with constipation that results in either encopresis or even one bout of fecal impaction should receive therapy with a logical plan. Disimpaction should be done before any laxative therapy is started. It may be performed with a water-soluble contrast enema or with enemas administered three times daily until the child's colon is clean, as demonstrated on abdominal radiographs. Severe cases require operative disimpaction with general anesthesia. Failure to disimpact followed by premature use of laxatives leads to severe abdominal pain.

Enemas function in two ways: They wash the colon in proportion to their volume, and they stimulate a contraction in proportion to their irritant, which may be salt, phosphate, glycerin, or a combination thereof. The basis of most enemas is saline, and volumes are 10-15 mL/kg. This amount is larger than what many physicians are used to prescribing but is often necessary in patients with severe constipation.

For patients receiving a thrice-daily disimpaction regimen, only one of the daily enemas should include phosphate to avoid any risk of hyperphosphatemia. Enemas must be slowly administered, over several minutes, and the solutions must be between room temperature and body temperature. Enemas that are too cold or too rapidly administered can cause vagal responses and syncope. (See the image below.)

Enema administration. Enema administration.

After cleaning is achieved, the child may start taking laxatives. Starting laxatives before complete cleaning may result in crampy pain and emesis and may cause the patient or parent to lose faith in the therapy.

Mild cases of constipation in babies can often be treated by adding 5-15 mL of prune juice to one bottle daily; adding more than this may result in gas cramps. For babies who do not spontaneously release stool and who do not have Hirschsprung disease, glycerin suppositories are extremely helpful in inducing a bowel movement.

Older children with mild constipation may respond well to a nonstimulant laxative, such as GlycoLax. This is a powdered form of ethylene glycol, a common bowel preparation used to wash out the intestine before surgery or endoscopy. It comes as a powder and may be easily mixed in any beverage with minimal taste, making it ideal for children. This laxative may be used alone or in combination with a fiber supplement.

Soluble fiber, such as psyllium, pectin, methylcellulose, and bran, can be a vital part of a constipation regimen. Soluble fiber absorbs water and binds fat in the stool. It is essentially a stool normalizer and not a laxative, though it may behave as a laxative when taken in excessive doses. If the stool is too hard, soluble fiber makes it softer. If the stool is too loose, the fiber firms it up. Various commercial fiber preparations are available, and some are made palatable to children by becoming almost flavorless in any beverage.

For healthy adults without constipation, the recommendation is to add fiber to their diet in the amount of 15-30 g/day. Converted for children, this dosage is roughly equivalent to 0.25-0.5 g/kg/day. This would be a recommended dosing of fiber for children without motility issues. Most children with motility problems require a higher dosage than this; the daily dose can easily be increased to achieve effectiveness.

For children with complicated constipation who need more than simple fiber and GlycoLax, senna-based stimulant laxatives are highly effective. Many different brands of senna-based laxatives are on the market. Senna is a naturally occurring herb that induces a bowel movement several hours after its ingestion.

Whatever form of laxative is chosen, the appropriate dosage can be determined by using an escalating laxative-dosing protocol. An initial dosage is chosen, and the patient's response is observed the next day. If a massive bowel movement occurs, it is confirmed with a radiograph; that dosage is then continued as long as it continues to work.

If the patient has an absent or inadequate bowel movement, an enema is administered in the evening to remove the past 24 hours' worth of stool, and the laxative dosage is then increased. This procedure is continued until the laxative dosage that works for 24 hours' worth of stool is found or until the patient vomits from the massive dosage of laxatives.

If the patient can achieve a complete bowel movement (as confirmed with regular radiography) on a given laxative dosage, that dosage is continued for as long as necessary. The course of treatment is not simply a few weeks or months and cannot be stopped once the child’s condition improves. If treatment is discontinued, symptoms recur and the child becomes frustrated. This frustration may be averted by clearly informing the patient at the outset that the condition is manageable but presently incurable (though a cure may be found in the future).

If an effective laxative dosage cannot be established or if ingestion of massive quantities of laxative has resulted in vomiting, the child may benefit from surgery or a bowel-management enema regimen. If the child has an isolated megarectosigmoid colon, resection of that segment with primary anastomosis may be offered. If the same child has either pancolonic dilation or no dilation at all, resection is not an option. If surgery is not an option or if the parents do not want surgery, an enema regimen can be instituted.

These enemas are similar to those previously described and are titrated over 5 days to establish the precise enema type and volume that keeps the child clean for a 24-hour period. This regimen allows the child to function socially without any perceived difficulty. The enema must be administered every day for as long as the child has this problem. In situations where enemas are ineffective for whatever reason, an ostomy might be necessary.

It should be kept in mind that as children age and grow and as their diets and social situations change, the dosage of laxative or the volume and type of the enema may need to be adjusted. The regimen should be continued until the child is old enough to attempt weaning away from the laxatives while increasingly working with diet and fiber to reduce the need for laxatives. Some patients may achieve excellent results with this approach, but they must be completely self-motivated and committed to dietary limitations. Others may require laxatives indefinitely.

Ng et al studied transanal irrigation (TAI) 42 patients with intractable fecal incontinence and constipation, of whom 62% were diagnosed with idiopathic constipation, 26% with anorectal malformation, 5% with Hirschsprung disease, 5% with spina bifida, and 2% with gastroschisis.[9] In all, 84% of the adopters responded to treatment. The investigators concluded that TAI is a safe and effective treatment for intractable constipation/fecal incontinence in children that can significantly improve quality of life if tolerated.

Surgical Therapy

Surgical procedures for idiopathic constipation are controversial.[10] For children with isolated dilation of the rectosigmoid colon that is not manageable with laxatives or that requires massive amounts of daily laxatives, resection of the dilated segment with anastomosis at the level of the peritoneal reflection may improve the situation.

Preoperative intestinal preparation before bowel resection is done at the surgeon's discretion. For any child with suspected impaction, preoperative disimpaction using an enema or digit may be required. Such patients should undergo intestinal preparation to minimize the risk of spillage during surgery and to facilitate exposure.

Anastomosis is performed at the level of the peritoneal reflection, which often corresponds to the junction of the upper and middle thirds of the rectum. Some authors have advocated resecting down to the anus with coloanal anastomosis, and others advocate coloanal anastomosis performed in an endorectal fashion (such as the Soave procedure for Hirschsprung disease).

When the descending colon is brought down to the anus, the resulting motility pattern is often more rapid than what the patient can tolerate and may result in soiling or even total incontinence. When the anastomosis is performed at the level of the peritoneal reflection, some rectal reservoir is left; although this rectum is also hypomotile, mild residual constipation is better than incontinence, which is the risk assumed by resecting low in the pelvis.

Children without isolated rectosigmoid dilatation who eventually require an enema regimen for bowel management may be offered some form of cecostomy. This procedure allows the child or adult the ability to self-administer antegrade enemas, increasing his or her freedom and quality of life.[11] Continent appendicostomy is an excellent option, though complications (eg, stenosis and leakage) can occur. Another approach is button cecostomy. Complications of the latter procedure include leakage, peritonitis, and wound breakdown. Laparoscopic-assisted percutaneous endoscopic cecostomy (LAPEC) has been found to be safe and effective.[12]

When cecostomy fails to result in successful bowel management, total or segmental colon resection may lead to resolution or improvement of symptoms in some patients.[13]

Diverting ostomy is reserved for patients with total colonic dysmotility whose condition is unmanageable with either laxatives or enema regimens. All such patients should be evaluated with total colonic manometry to help discern between true pseudo-obstruction and other etiologies. Regimen compliance can often be an issue in these patients.

Complications

The complications associated with treatment of colonic dysmotility syndromes generally fall into the following two categories:

  • Consequences of inadequate treatment
  • Complications of surgery

The most common adverse outcome is fecal incontinence and soiling. This is devastating for a child who becomes accustomed to the problem after years in diapers and who is unaware of the smell of feces. Other children quickly become aware of this problem and can be extremely cruel. These children should be rendered clean before they enter school.

Inadequate treatment resulting in fecal incontinence and soiling often arises from gross underestimation of the severity of the problem by both parents and physicians. Physicians often dose laxatives by simply following the instructions on the box, which usually underestimate what many of these children need, and they apply both laxatives and enemas haphazardly, without proper coordination of efforts. This approach results in patient and parent frustration and continued accumulation of stool, eventually leading to fecal impaction and overflow incontinence.

Only in rare cases are surgical procedures for idiopathic constipation indicated. Resections and pullthrough procedures always pose a risk of incontinence. Other procedures include sphincteric myotomy, myectomy, and injection of onabotulinumtoxinA. These procedures are done for ultrashort Hirschsprung disease or achalasia of the sphincter and can also result in incontinence. (If injections of botulinum toxin result in incontinence, it should last only several months.)

Long-Term Monitoring

Long-term follow-up is essential to prevent incomplete stooling and eventual fecal impaction in patients with colonic motility problems.

At present, idiopathic constipation is incurable. Inability to accept this fact on the part of parents or patients often makes this condition especially frustrating for them. If patients and parents are given the impression that the child will be able to stop therapy and stool normally after a few months of therapy, frustration will inevitably ensue when the problem recurs. If patients and parents are prepared at the outset for a problem that, though chronic, is manageable, the frequency of recurrences will decrease and the patient's quality of life improve.

Surgery for pediatric colonic dysmotility is rarely curative. For children to be cured, they should become able to empty their rectums without the use of special diet or laxatives and without internal accumulation of incompletely evacuated stool. This is rarely the case.

Surgery can be extremely beneficial in that it can render the child's condition more manageable than before. Most children require substantially lower laxative doses after sigmoid resection. In the case of children whose conditions were unmanageable with laxatives and who depend on enemas, some become able to function with laxatives alone. All children must be closely monitored after surgery and must be given realistic expectations before surgical options are considered.

When patients are doing well, they should be examined at least every 6 months while they are growing, with immediate intervention for any problems that arise. Plain radiography is performed whenever complete emptying is questioned. Contrast enemas need not to be performed to see if colonic dilation improves over time.

As children grow, they require increasing amounts of laxatives. For children using enema regimens, the volume and formula of the enema are likely to require some adjustment.