Pediatric Primary Care Case Studies (32 page)

•   Is there a family history of constipation or encopresis?

•   Are restrooms at school or daycare available when needed and acceptable by the child for use?

•   What treatments, medications, and/or strategies have been utilized in the past?

In addition, inquire about dietary history, exercise patterns, and behavioral history—what are normal behaviors for this child. A psychosocial history that includes seeking information about members of the household, alternative caregivers, and interactions with family members and peers should also be obtained.

What other conditions might cause stooling problems?

A history of stool withholding behavior reduces the likelihood that there is an organic disorder (Baker et al., 2006). Organic causes account for only 5% of cases of constipation and include anatomic, neuromuscular, metabolic, or endocrine causes (Castiglia, 2001). The most common organic etiology for constipation is Hirschsprung disease. The absence of ganglion cells in the muscle of the rectum does not allow relaxation of the rectal walls, thus not allowing feces to enter into the anal canal. These children are typically identified when there is no passage of meconium stool shortly after birth or upon evidence of bowel obstruction in the newborn period. Interestingly, most children with Hirschsprung disease never have soiling (Castiglia).

Anatomic defects of the spine and anus can also lead to constipation and encopresis. The most common of these include meningomyelocele (spina bifida), tethered cord syndrome, and imperforate anus with fistula (Coughlin, 2003).

Metabolic and endocrine abnormalities that promote constipation and subsequent stool holding include hypothyroidism, hypokalemia, and hypercalcemia, as well as lead intoxication, cystic fibrosis, celiac disease, and diabetes mellitus (Coughlin, 2003).

You talk with Zachary and his mother. The following information emerges from your interview:

Zachary was the full-term product of a normal vaginal delivery. He produced meconium stool in the first hours of life. He has been well and healthy. You also elicit a history of difficulty with toilet training. He had toilet resistance and had bowel movements in his pull-up diapers until he was 4½ years old. Zachary has always had large diameter stools that frequently clogged the toilet, and he typically has a bowel movement every 3 days. No blood has been noted on his stools, and there has been no evidence of anal fissures.

Since he started school, his parents have minimal knowledge of his toileting behaviors and assume he is defecating regularly. However, they really don’t know. Zachary can’t remember the last time he had a stool in the toilet. The nearest bathroom to his classroom is down the hall. The teacher does not allow students to freely use the restroom; they must raise their hand to get permission and then carry a large red key that signals bathroom permission. Zachary hates to use the bathroom at school.

Zachary had been continent for urine both day and night since 3 years of age. In the past year, he has been incontinent for daytime urine one to three times per week, with urinary dribbling. He insists he does not feel the urge to urinate until it is too late and he wets himself. Zachary is the youngest of three children; both parents work full time. His middle school brother watches him after school for 2 hours until his parents get home. Zachary is quite active at home, enjoying biking, rollerblading, and basketball. He has avoided team sports because he is worried about public soiling. He enjoys the computer and plays computer games for hours at a time.

What aspects of the physical examination will be important in this case?

Physical Examination

It is necessary to perform a thorough physical examination as part of the evaluation of the child with encopresis. Examination of the external perineum for skin tags, anal position, and anal tone gives clues to an anatomical or inflammatory condition. Inspection of the lower back for pigmentary irregularities, sacral dimples, tufts of hair, or asymmetry of the spine can give clues to a neurologic abnormality. Digital exam of the anorectal area is recommended. It gives immediate indication of sensation, anal tone, the size of the rectum, and the presence of anal wink. It also determines presence of a fecal mass in the rectum and the amount and consistency of rectal stool.

The abdominal exam requires palpation for assessment of the amount of retained fecal matter. A neurological examination will detect signs of spinal nerve involvement, which can be responsible for abnormal sphincter function from a spinal cord tumor or a tethered cord. Assessment of lower extremity tone, strength, and deep tendon reflexes is warranted as well as evaluating the cremasteric reflex. Detection of a physical abnormality could lead to the identification of an organic disorder (see
Table 9-2
).

Should you order any laboratory or radiology studies?

In most patients, the diagnosis is established with the history and complete physical examination, including the rectal exam (Baker et al., 2006). Generally speaking, diagnostics are not warranted, except in those children who fail medical management or who have a red flag identified on history and/or physical examination. A KUB can be helpful for evaluating the amount of stool in the colon when the history is unclear; when palpation of the abdomen may be difficult, as with obese children; or sometimes to convince a family there is backed up stool in the colon (Baker et al., 2006). Most often a KUB is done to assess the effectiveness of a bowel clean-out or provide clarity once medical management has begun.

Laboratory studies are seldom warranted. These are typically ordered when patients have failed medical management and/or families need further evidence because encopresis is typically a functional disorder. If additional testing is needed, the healthcare provider should consider the need for such studies as a complete metabolic panel (screen for calcium, potassium, and electrolytes), sedimentation rate, thyroid studies (free T4, TSH), IgA and tissue transglutaminase IgA to screen for celiac disease, and a lead level. If indicated, screen for cystic fibrosis with a sweat chloride test.

When considering tethered cord because of persistent urinary dysfunction despite an effective bowel clean-out, a screening radiograph of the lower spine looking for spina bifida occulta can be helpful. About 98% of people with tethered cord have spina bifida occulta, but 10–20% of the normal population has spina bifida occulta without adverse sequelae. The most definitive diagnostic test for tethered cord is magnetic resonance imaging (Rosen, Buonomo, Andrade, & Nurko, 2004). Once tethered cord is identified, a neurosurgical referral is necessary. Hirschsprung’s disease can be identified by barium enema and/or rectal biopsy.

Upon physical examination, you find Zachary is at the 70th percentile for height and weight with a BMI of 17, which is at the 75th percentile. Vital signs are within normal limits. He is well developed. Head, ears, eyes, nose, and throat are all normal and without palpable lymphadenopathy. His heart has a regular rate and rhythm and no murmur is auscultated. Lungs are clear with good aeration bilaterally. The abdomen is rounded and slightly tense with a hard palpable mass from the suprapubic area to his umbilicus. There are ropey loops of bowel palapated in the left lower quadrant and right lower quadrant, without tenderness. Rectal examination reveals a normotonic, normally placed anus without skin tags or fissures and a positive anal wink. There is pasty thick stool in moderate amounts around the anus. The digital examination reveals a rectum full of hard stool, which is guaiac negative. When the patient is asked to expel the examining finger, there is rectal tightening of the external anal sphincter (EAS) rather than expected relaxation.
No dimples or tufts of hair are noted. The spine is straight. Strength and deep tendon reflexes in the lower extremities are normal and symmetric.

Making the Diagnosis

The history and physical examination are consistent with the diagnosis of retentive encopresis. He has a history of not wanting to use the restroom at school resulting in fecal withholding, fecal accidents, wearing pull-up diapers, no sensation of stooling, and sitting in his soiled underwear until his parents tell him to clean up. His physical examination is normal except for palpable stool in his abdomen and rectal tightening response.

Management

How do you plan to treat this child with encopresis?