Constipation

Key Features

• Most constipation in childhood is a result of voluntary or involuntary retentive behavior (chronic retentive constipation)

• About 2% of healthy primary school children have chronic retentive constipation

• Ratio of males to females may be as high as 4:1

Clinical Findings

• Chronic constipation in childhood is defined as two or more of the following characteristics for 2 months:

  • Fewer than three bowel movements per week

  • More than one episode of encopresis per week

  • Impaction of the rectum with stool

  • Passage of stool so large it obstructs the toilet

  • Retentive posturing and fecal withholding

  • Pain with defecation

Diagnosis

• Infants younger than 3 months often grunt, strain, and turn red in the face while passing normal stools

• Failure to appreciate this normal developmental pattern may lead to the unwise use of laxatives or rectal stimulation

• Infants and children may, however, develop the ability to ignore the sensation of rectal fullness and retain stool.

• The dilated rectum gradually becomes less sensitive to fullness, thus perpetuating the problem

• Retention of feces in the rectum can result in overflow incontinence (encopresis) in 60% of children with constipation

Treatment

• For mild constipation, increased intake of water and such foods as bran, whole wheat, fruits and vegetables, may be sufficient

• Medications may be required when dietary modification is not enough; following are safe stool softeners for infants and children

  • Polyethylene glycol solution (MiraLax), 0.8–1 g/kg/d

  • Lactulose, 1–2 g/kg/d

  • Milk of magnesia

    • For 2–5 years old, 400–1200 mg/d

    • For 6–11 years old, 1200–2400 mg/d

• Stimulant laxatives such as Senna or Bisacodyl can be considered as an additional or second-line treatment

• A recent study showed lubiprostone (Amitiza) was efficacious and well tolerated in children and adolescents with functional constipation. Lubiprostone is a prostone that, acting locally as a specific activator of chloride channel protein-2 in the GI epithelium, promotes intestinal secretion of chloride ions and fluid, enhancing GI motility.

• Encopresis

  • If present, first, relieve fecal impaction

  • Disimpaction can be achieved in several ways, including

    • Saline enemas

    • Polyethylene glycol (MiraLax), 1 g/kg/d

    • Milk of magnesia, 1–2 mL/kg/d

  • Recurrence is common; should be treated promptly with a short course of stimulant laxatives or an enema

• Effective stool softeners should thereafter be given regularly in doses sufficient to induce very soft daily bowel movements

• After several weeks to months of regular soft stools, stool softeners can be tapered and stopped

• Mineral oil

  • Should not be given to nonambulatory infants, physically handicapped or bedbound children, or any child with gastroesophageal reflux

  • Aspiration may cause lipid pneumonia