Pediatric Colonic Motility Disorders Treatment & Management

Updated: Jul 05, 2016
  • Author: Nelson G Rosen, MD, FACS, FAAP; Chief Editor: Harsh Grewal, MD, FACS, FAAP  more...
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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. (See the image below.) The clinician should personally direct an aggressive course of nonoperative treatment before considering a surgical option. (See Treatment.)

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.

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Medical 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. [8] 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.

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Surgical Therapy

Surgical procedures for idiopathic constipation are controversial. [9] 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. [10] 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.

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. [11]

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.

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Complications

The complications 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.)

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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.

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