Constipation


(25% of all GI visits)

Definitions:
** INFANCY:
If meconium passage is delayed for more than 24 hours, Consider: Hirschsprung disease (HD) and anatomic defects of the spinal cord or anorectal malformations. A meconium plug may cause neonatal constipation and may be associated with either HD or cystic fibrosis

Functional Constipation (90% of all constipation)

Diagnostic criteria must include:

TWO or more of the following for at least 1 month in infants up to 4 years

  1. Two or fewer defecations per week
  2. History of excessive stool retention
  3. History of painful or hard bowel movements
  4. History of large diameter stools
  5. Presence of a large fecal mass in the rectum
  6. At least one episode of fecal incontinence per week after the acquisition of toileting skills
  7. History of large-diameter stools that may obstruct the toilet in toilet trained children
 
TWO or more symptoms at least once per week for at least 1 month in children 4 years or older:
 
  1. Two or fewer defecations per week
  2. At least one episode of fecal incontinence per week
  3. History of retentive posturing or excessive stool retention 
  4. History of painful or hard bowel movements 
  5. Presence of a large fecal mass in the rectum 
  6. History of large-diameter stool that may obstruct the toilet 
  7. Additional criteria: without fulfilling irritable bowel syndrome criteria

Functional Fecal incontinence

(Primary = never toilet trained, Secondary = occuring after toilet training)
  1. Constipation associated fecal incontinence
  2. Functional nonretentive fecal incontinence (FNRFI) - if no history of constipati
Diagnostic criteria for FNRFI must include ALL OF THE FOLLOWING in children at least 4 years of age, for at least 1 month prior to diagnosis:
  1. Defecation into places inappropriate to the social context
  2. The fecal incontinence cannot be explained by another medical condition after appropriate medical evaluation
  3. No evidence of fecal retention

Note: Patients with FNRFI will have normal colonic transit times (Sitz Marker or WMC), rectal compliance, and sensitivity thresholds (ARM) unlike incontinence associated with constipation

Colonic transit time (CTT) or sitz marker test can determine if patient has:
1. Normal colonic transit
2. Colonic intertia (slow transit constipation)
3. Outlet obstruction -most common in peds constipation

CTT- Not a good test for Dx of constipation but can differentiate between constipation and FNRFI (normal transit)

Etiology of non-functional constipation (10%)


Intestinal causes:  Hirschsprung disease, Anorectal malformation (imperforate anus, anal stenosis), Neuronal intestinal dysplasia, Colonic inertia

Neuropathic conditions: Spinal cord abnormalities, Spinal cord trauma, Neurofibromatosis, Static encephalopathy, Tethered cord, pelvic mass/ sacral teratoma

Metabolic/ Endocrine causes: Hypothyroidism, Diabetes mellitus, Hypercalcemia, Hypokalemia, Vitamin D intoxication

Drugs: Opioids, Anticholinergics, Antidepressants

Other causes: Anorexia nervosa, Botulism, Sexual abuse, Scleroderma, Cystic fibrosis, Dietary protein allergy, abnormal abdominal musculature (prune belly, down), MEN Type 2B

Evaluation:

History
-Timing of first meconium stool
-Family definition of constipation
-Duration of condition/ age of onset
-toilet training status
-Stool size, consistency, fequency
-Pain with stool
-Blood with stool
-Abdominal Pain
-Abdominal Distension
-Soiling of underwear, description
-Withholding behavior (may appear to be straining/pushing)
-Change in appetite/ Anorexia -loss of appetite for food
-Nausea/Vomiting
-Weight loss or poor weight gain
-Previous treatment strategies tried
-Dietary History
-Allergies
-Medications
-Developmental history
-Social Hx
-School toilet habits
-Possibility of abuse
-Fam Hx

Alarm Signs
-Constipation starting extremely early in life (<1 mo)
-Passage of meconium >48 h
-Family history of HD
-Ribbon stools
-Blood in the stools in the absence of anal fissures
-Failure to thrive
-Fever
-Bilious vomiting
-Abnormal thyroid gland
-Severe abdominal distension
-Perianal fistula
-Abnormal position of anus
-Absent anal or cremasteric reflex
-Decreased lower extremity strength/tone/reflex
-Tuft of hair on spine
-Sacral dimple
-Gluteal cleft deviation
-Extreme fear during anal inspection
-Anal scars

Physical Exam
-Measurement of weight and height
-Abdominal exam:
-Evaluation of the perianal region:
-Digital Rectal exam (DRE): (a digital rectal exam may not be necessary for the diagnosis if the child already fulfills two other clinical Rome IV criteria for functional constipation)
 
-BACK: The lumbosacral area should be inspected for the presence of signs of spina bifida occulta.

Treatment


Treatment of functional constipation
CLEANOUT (impaction):
1. MiraLax (PEG) 1 - 1.5g/kg for 3-6 days is recommended as first line treatment
2. Enema once daily for 3-6 days if PEG not available

MAINT:
1. Miralax (PEG) should be first line for maintenance: 0.4g/kg (titrate for effect)
2. Enemas not recommended
3. Lactulose can be used if PEG not available
4. Milk of Magnesia, mineral oil, and stimulent laxatives may be considered as second line treatment
5. Treatment should continue for at least 2 months with resolution of symptoms for at least 1 month before discontinuation.
6. If toilet training: medication should only be discontinued, when toilet training achieved


Normal Fiber intake, Water intake, and activty level is recommended

Not currently recommended:
-Prebiotics
-Probiotics
-Intensive behavioralized protocol
-Biofeedback

Prognosis
50% recover and are laxative free after 6-12mo
80% recover within 10 years

Summary of NASPHGAN recommendations:


Diagnostic Recommendations
  1. The Rome III criteria are recommended for the definition of functional constipation for all age groups.
  2. The diagnosis of functional constipation is based on history and physical examination.
  3. We recommend using alarm signs and symptoms and diagnostic clues to identify an underlying disease responsible for the constipation.
  4. If only 1 of the Rome III criteria is present and the diagnosis of functional constipation is uncertain, a digital examination of the anorectum is recommended.
  5. In the presence of alarm signs or symptoms or in children with intractable constipation, a digital examination of the anorectum is recommended to exclude underlying medical conditions.
  6. The routine use of an abdominal radiograph has no role to diagnose functional constipation.
  7. A plain abdominal radiography may be used in a child in whom fecal impaction is suspected but in whom physical examination is unreliable/not possible.
  8. Colonic transit studies are not recommended to diagnose functional constipation.
  9. A colonic transit study may be useful to discriminate between functional constipation and functional nonretentive fecal incontinence and in situations in which the diagnosis is not clear.
  10. Rectal ultrasound is not recommended to diagnose functional constipation.
  11. Routine allergy testing to diagnose cow’s-milk allergy is not recommended in children with constipation in the absence of alarm symptoms.
  12. Based on expert opinion, a 2- to 4-week trial of avoidance of CMP may be indicated in the child with intractable constipation.
  13. Routine laboratory testing to screen for hypothyroidism, celiac disease, and hypercalcemia is not recommended in children with constipation in the absence of alarm symptoms.
  14. Based on expert opinion, the main indication to perform ARM in the evaluation of intractable constipation is to assess the presence of the RAIR.
  15. Rectal biopsy is the gold standard for diagnosing HD.
  16. We do not recommend performing barium enema as an initial diagnostic tool for the evaluation of children with constipation.
  17. Colonic manometry may be indicated in patients with intractable constipation before considering surgical intervention.
  18. The routine use of MRI of the spine is not recommended in patients with intractable constipation without other neurologic abnormalities.
  19. We do not recommend obtaining full-thickness colonic biopsies to diagnose colonic neuromuscular disorders in children with intractable constipation.
  20. We do not recommend the routine use of colonic scintigraphy studies in children with intractable constipation.

Therapeutic Recommendations


References
Harriet Lane
https://www.naspghan.org/files/documents/pdfs/cme/jpgn/Evaluation_and_Treatment_of_Functional.24.pdf