Pediatric Constipation

What is Constipation?

• Constipation: Infrequent bowel movements, painful defecation, or larger and harder stools which require excess straining
• Functional Constipation: Persistent constipation that is not due to an anatomical or neurologic cause.
  • Recent Onset Constipation: Lasts for less than 8 weeks. Responds to short term laxatives or behavior modification
  • Chronic Constipation: Lasts over 3 months. Requires long term laxatives and more intense behavior modification

When is constipation most common in kids?

• Introduction of solid foods or cow milk:
  • Solids can cause constipation due to inadequate fluid and fiber. Fiber can be added with fruits, vegetables, and cereals (but not rice). Adding more than the recommended amount of fiber does not help.
  • Cow milk can increase the risk of constipation as well as anal fissures. It can be replaced with calcium-fortified soy milk.

• Toilet Training:
  • Children may not respond to need to defecate, and may have difficulty with leverage if their feet don’t touch the ground.
  • This may lead to withholding, which will cause stools to become larger and harder. Laxatives would be needed to treat this.
  • Toilet training should be done with a routine, relaxed, child-oriented approach.

• School Entry:
  • Children may be afraid to defecate at school, or the change in schedule may make it more difficult. This may lead to withholding. Also, as children start to use the bathroom themselves, parents may become less aware of their child’s bathroom habits.
  • Parents should frequently ask about child’s bathroom habits. Furthermore, parents should continue to monitor fiber intake.

Chronic Constipation

• Apart from the usual symptoms of constipation, chronic constipation can present with:
  • Urinary incontinence or bladder disease (since the rectum can push on the bladder)
  • Weight loss or poor weight gain
  • Delayed growth
• Signs of a chronic condition
  • Presentation at birth or early infancy
  • Symptoms outside of the GI tract (especially neurologic conditions)
  • Physical findings of anorectal abnormalities
  • Congenital syndromes such as Down Syndrome
  • Family History of Hirschsprung Disease

Other causes of constipation in children

• Infant Dyschezia:
  • Significant straining and crying before stools in infants in the absence of constipation. Likely due to inadequate relaxation of pelvic floor or weak abdominal muscle tone
  • This condition usually resolves on its own. Doctors must differentiate this from anal fissures or food-protein induced proctitis.
• Hirschsprung Disease
  • This is a congenital lack of ganglion nerve cells in the colon, so the colon is unable to relax
  • It is usually diagnosed within the first week of life after a failure to pass meconium. It can present with abdominal distention and vomiting. Rarely, a milder form can present in older children.
  • It is important that this disease is diagnosed and treated quickly

Other causes of constipation in children

• Slow Transit Constipation
  • Patients have slow movement of food through the colon, without another underlying disease. This is treated with laxatives and behavior modification, but the treatment is less effective than with functional constipation
• Anorectal Abnormalities
  • This can include an imperforate anus or an anteriorly displaced anus. This needs to be treated surgically
• Cystic Fibrosis
  • This is a genetic disorder most common in white children. It is often detected in genetic screens.
  • As an infant it can present with a failure to pass meconium. As the child grows, they will get recurrent pulmonary infections and pancreatic insufficiency. It can also present with constipation
• Celiac Disease
  • Celiac Disease is a sensitivity to gluten that usually presents with diarrhea. It can, however, also present with constipation.

Constipation in adolescents

• Slow-transit constipation is more common in teenagers
• Constipation in teenagers may be related to eating disorders, school stressors, and ADHD.

Physical Exam for Constipation

• General: Check child growth, weight
• Abdomen: Tenderness, distension
• Neurologic: Sensory and motor. Tone and reflexes. Cremaster reflex. Patulous (loose) anus suggests sphincter tightening
• Perineum: Anorectal development
• Digital Rectal Examination:
  • This is suggested for the following situations
    • Infants with constipation
    • Children with constipation since early infancy
    • Symptoms that suggest underlying disease
  • Findings
    • May had explosive release with DRE
    • Tight anal canal with empty ampulla suggests Hirschsprung Disease

Imaging and Labs

• Imaging
  • Imaging is indicated if history is inadequate and the physical exam is inconclusive or the patient won’t cooperate with the PE
  • Barium Enema: This can provide evidence of Hirschsprung Disease
  • Spinal X-Ray/MRI: This should be done if there is evidence of neurologic impairment in the perianal area or lower extremities
• Labs
  • Celiac Screening: Check for celiac with failure to thrive and recurrent abdominal pain
  • Urinalysis: If there is evidence of rectosigmoid impaction, the bladder may be compressed, which may lead to infection
  • TSH: If there is evidence of hypothyroidism (poor growth fatigue, depressed reflexes)
  • Electrolytes: Especially Calcium
  • Blood Lead Level: For children with risk factors (Living in an old house, relative with lead poisoning)

Treatment

• Infants
  • Sorbitol containing fruit juices such as prune or apple juice can be used. If they are old enough they can get fruit purees.
  • Infants older than 6 months can be given laxatives such as polyethylene glycol (MiraLAX), sorbitol, or lactulose
• Toddlers and children
  • If defecation is not painful, and increase of fiber (whole grains, fruits, vegetables) and fluids can be given
  • If defecation is painful, laxatives can be used
    • If there are anal fissures, they can be treated with petroleum jelly
  • Disimpaction may be needed (see next slide)
  • Behavior Modification
    • Encourage child to sit on the toilet at regular times after meals
    • The child’s feet should be supported (with a stool if necessary)
    • Rewards (never punishments) should be given to encourage the child

Disimpaction

• Fecal Impaction: Markedly increased stool in the colon and rectum
  • When should a child be disimpacted?
    • Constipation-associated fecal incontinence
    • Significant stool mass felt on digital rectal examination or seen on abdominal X-ray
    • History of incomplete or infrequent evacuation
  • How to disimpact
    • Can be done in the outpatient setting, but hospitalization may be necessary if treatments are unsuccessful
    • Solutions such as polyethylene glycol or mineral oil can be given through an oral, nasogastric, or rectal route
    • A combination or oral and rectal is the most effective
    • Glycerin suppositories or rectal stimulation can be used, but should not be first line , as the child can become dependent on them for defecation

Parent Education

• Parents should understand that refusing to defecate or stooling due to overflow incontinence is not “bad” behavior, and the child cannot control it.
• In cases of constipation, toilet training should be postponed as will not be effective until the constipation is treated.
• Even after constipation is treated, it may take a few months until the nerves readjust and the child learns to use rectal muscles to control defecation
• It is important that parents and child regularly follow up with the pediatrician

Bibliography

• Sood, Manu. “Recent-onset constipation in infants and children”. UptoDate. June, 2020.
• Sood, Manu. “Constipation in infants and children: Evaluation”. UptoDate. June, 2020.
• Sood, Manu. “Constipation in infants and children: Treatment”. UptoDate. June, 2020.
• Sood, Manu. “Functional constipation in infants, children, and adolescents: Clinical features and diagnosis”. UptoDate. June, 2020.