CHILDHOOD CONSTIPATION

Childhood constipation is very common and most have no organic cause.  Some require extensive evaluation for things like Hirschsprung disease and metabolic disorders, but they generally have obvious warning signs:  failure/delay of meconium after birth, failure to thrive, or severe abdominal abnormalities.  Most are transient in nature and can be treated with therapy for fecal impaction and oral laxatives.

Constipation can affect up to 1/3 of children worldwide, and be the reason for up to 1/4 of pediatric doctor visits.  The health system can spend up to three times as much on constipated children versus those who are not.

For children younger than four years old, the Rome III Diagnostic Criteria for Diagnosing Functional Constipation in Children is used:

 Must have at least two of the following:
Straining on at least 25% of defecations
Lumpy/hard stools on at least 25% of defecations
Sensation of blockage on at least 25% of defecations
Manuel maneuvers are needed on at least 25% of defecations
<3 defecations/week

Generally the criteria is fulfilled for 3 months with symptom onset at least 6 months prior to diagnosis.  However, research supports favorable outcomes if therapy is started prior to meeting the timeframe. 
Normally an infant will have 2-3 stools/day for the first week of life, 2/day into toddler years, and 1/day after 3 years of age.  Some breastfed babies only have bowel movements every week or two.  In these children, as long as the bowel movement is watery or soft when they finally have it, then they are likely normal and not constipated. Why do breastfed babies have such infrequent bowel movements? Most people believe it is because breast milk gets digested so well that there is not much left over to make bowel movements.

Painful bowel movements will cause the child to VOLUNTARILY withhold stool.  As the child consciously holds stool, they may develop habits like hiding, rocking, or fidgeting.  This causes stool stasis, more water absorption (harder stools), and larger stools.  Once the rectum is stretched to a certain point, both anal sphincters (involuntary and voluntary) are overcome and fecal incontinence can develop.  This cycle can still develop with non-painful bowel movements if changes or stressors are introduced (starting toilet training, changes in diet, family stress, illness, etc).

A good history and physical can be used to distinguish functional vs organic constipation, and help avoid invasive tests.  Be mindful that a good history will consist of accurate frequency, consistency, stool size, pain, bleeding, timing of first bowel movement after birth, fecal incontinence, withholding behaviors, systemic symptoms (fever, vomiting, etc), social stressors, diet, and medications.

Education and behavior modification are the first step in treatment.  It must be understood that fecal incontinence is from involuntary overflow and not voluntary withholding.  Regular toiling  after meals combined with a reward system is often helpful.  To help reduce stress and constipation exacerbation, family members are to remain positive and supportive.

Infants under 6 months will generally need more fluids and soften stools.  2oz/day of prune is recommended along with good hydration, but excess water intake doesn’t support resolving constipation.  Recent research does not support the use of fiber supplements or probiotics in treating functional constipation, but may be beneficial during maintenance periods.  Studies have found no differences from oral laxatives to enemas on disimpaction, but oral laxatives are generally preferred by most.

Oral Laxatives:
    Lactulose    1-2 g/kg, 1-2/day
    PEG 4000 (polyethylene glycol)    1-1.5 g/kg/day    Max of 6 consecutive days
    Milk of Magnesium 2-5 y        0.4-1.2 g/day  Once or divided
            6-11 y            1.2-2.4/day  Once or divided
            12-18 y         2.4-4.8 g/day Once or divided

Polyethylene glycol (Miralax) is most likely to cause fecal incontinence than other oral laxatives, so milk of magnesium is generally preferred during maintenance therapy:
    Milk of Magnesium:
        < 2 y        0.5 ml/kg/day
        2-5 y        5-15 ml/day
        6-11 y         15-30 ml/day
        >11y         30-60 ml/day

Maintenance Therapy is very important as most children with functional constipation will have relapses and prolonged treatment therapies.  Maintenance therapy should continue for at least 2 months and all symptoms of constipation should be resolved for at least 1 month before discontinuing treatment. 

Approximately 80%of the children adequately treated early in their course recovered without using laxatives at 6-month follow-up, compared with only 32% of the children with a delay in treatment. These data indicated that early adequate therapeutic intervention was more likely to be beneficial and contributed to successful outcome of constipation.

Not Recommended:
    Dark Corn Syrup- Research does not support it laxative action and there is concern about the potential of carrying botulinum toxin, like honey.
    Mineral oil and stimulant laxatives (Senna, Bisacodyl)- should not used in infants and stimulants are only used in older children for rescue therapy when osmotic laxatives are ineffective.