Constipation (kids) 

• Constipation affects 5–30% of children and is responsible for 3% of primary care visits.
• Within the first three months of life, infants can pass anywhere from 5 to 40 motions per week
• decreasing at age one year to 4–20 motions per week and at three years to 3–14 per week

 

Clinical diagnosis

1. Rome IV criteria functional constipation – 2 or more of
   1. Two or fewer motions per week
   2. One episode incontinence per week
   3. Retentive posturing
   4. Painful/hard movements
   5. Large fecal mass in rectume
   6. Large diameter stools
2. Often occurs at times of starting solids, toilet training, school, can be associated with allergy e.g. Cows milk
3. Young childen ignore urge – painful apprehension – further retention
4. Faecal incontinence
   1. refers to the passage of stools in an inappropriate place, and may result from chronic retention of stool with passive overflow during withholding.
   2. Parents can interpret this passage of stool as the child trying to defaecate
   3. it is more likely that this incontinence is due to strong colonic contractions attempting to expel stool while the child is withholding, especially if there is associated retentive posturing.
   4. The presence of abdominal pain, distension, behaviour change and anorexia in these children may indicate a need for dis-impaction.

 

Organic causes to consider

1. Allergy – cow’s milk protein intolerance and/or other food protein intolerances
2. Coeliac disease
3. Hypothyroidism
4. Cystic fibrosis
5. Electrolyte abnormalities – hypercalcaemia, hyperkalaemia
6. Drugs – opiates, phenobarbital, anticholinergics
7. Neuropathic disorders – Hirschsprung’s disease, internal sphincter achalasia
8. Spinal cord abnormalities – myelomeningocele, tethered spinal cord, syringomyelia
9. Stooling may occur without sensation or urge
10. Anatomic malformations – imperforate anus, anteriorly displaced anus

 

Key points in the history

• When was the onset of constipation or soiling? What was the duration?
• What is the form and calibre of motions, frequency and relation to daily activity?
• Is there suspicion of an organic cause, or red flags in the history?
• Has the child been toilet-trained for stooling and/or urination?
• When and how often does the child sit on the toilet?
• What is the toileting posture? Are both feet resting on the ground or footstool and the child leaning forward with a relaxed abdomen?
• Are there triggering events (eg disrupted routine, entering day care or an episode of painful, hard stools leading to withholding)?
• Are there any neurodevelopmental concerns? Children with developmental delay or behavioural disorders will require additional help to be toilet trained.

• Determine the presence of any withholding behaviours. These include:
  • going stiff
  • clenching buttocks
  • walking on tip toes
  • crossing legs
  • bracing against furniture
  • being in all fours position or curling up in a ball
  • sitting with legs straight out.

• Factors associated with cow’s milk protein intolerance
  • Onset of symptoms on changing from breast to bottle feeds
  • Onset of symptoms on starting cow’s milk
  • Onset of symptoms on starting solid foods
  • Medication-resistant or medication-dependent constipation
  • Straining during defaecation, even in the presence of soft stools
  • Atopic disease – eczema, asthma, rhinitis
  • Rashes/urticarial with milk feeds/food
  • Irritability in infancy – reflux or vomiting
  • Voluntary dairy restriction
  • Family history – atopy, food allergy, food intolerance, autoimmune conditions

 

Physical examination

identify Red flags

 

Investigations

1. Not required unless other abnormalities or not responding
2. Assessment for 
   1. coeliac disease
   2. hypothyroidism
   3. hypercalcaemia 
   2. not recommended in children without alarm symptoms
   3. Testing, if required, includes
      1. immunoglobulin A (IgA)
      2. tissue transglutaminase (tTG) IgA
      3. thyroid function
      4. calcium
      5. electrolytes
   4. Allergy testing is not recommended
      1. to diagnose suspected cow’s milk allergy in children with constipation, as it is usually not IgE mediated
   5. Abdominal X-ray
      1. is not recommended to diagnose functional constipation
      2. magnetic resonance imaging of the spine is not required in those without neurological abnormalities in the primary care setting

 

Treatment

1. Usually required for several months- avoid long term bowel damage from impacted stool
2. Aim one easy motion per day
3. Management of functional constipation
   1. children who are not yet toilet-trained for stool, and who feel more secure defaecating in a diaper, this should be encouraged while the stool is softened with laxatives and the child regains confidence. 
   2. Toilet training should be child‑led. 
   3. Routine is important
   4. if old enough to comply, children should be encouraged to sit on the toilet for five minutes after every meal. 
   5. This can be used in conjunction with a rewards program such as a star chart

Behaviours

• Position — footstool to ensure knees are higher than hips. Lean forward and put elbows on knees. A toilet ring should be placed over the toilet seat if needed
• Toilet sits — up to 5 minutes, three times a day, preferably after meals. A timer in the bathroom can help. Encourage child to bulge out their abdomen. Praise child for sitting on toilet. Ensure toileting remains a positive experience
• Chart or diary — to reinforce positive behaviour and record frequency of bowel actions
• Encourage children to exercise more
• Review toilet access eg investigate barriers to using school toilets
• Delay toilet training attempts until child is painlessly passing soft stool
• Diet
• cow’s milk and soy protein
  1. one-month trial of avoidng cow’s milk and soy protein may be indicated in children with intractable constipation.
  2. During this period, calcium intake should be supplemented with almond or rice products, or calcium supplementation.
  3. Dairy intolerance can improve with time in older children but data in small children is limited.10 Dairy is tried in the diet every 6–12 months as tolerated. 

Drug therap

• Goals of drug therapy are to soften stools to eliminate the child’s fear of painful defaecation. 
• When discussing medication with parents, it is important they understand that the bowel does not become ‘dependent’ on the medication.
• Insufficient treatment can lead to long-term bowel damage from impacted stool. 
• Also, parents need to know that the stool will be made artificially soft, almost like diarrhoea, to allow the ‘stretched pipes’ to return to normal size, shape and function.
• treatment failure
  • insufficient dose and duration
  • poor compliance
• recurrence of trigger factors or alternative diagnosis. 

• First line treatment options
  1. Infants <1 month: Coloxyl drops
  2. Infants 1–12 months: Iso-osmotic laxative (Movicol Junior™ or Lactulose
  3. Children: Iso-osmotic laxative or lubricant (paraffin oil)
  4. Children with stool with-holding behaviours, pain while defecating or rectal bleeding or fissures may benefit from inpatient disimpaction management 
• Avoid enemas
• Petroleum jelly for fissures

Laxative	Dosage	Side effects
Osmotic oral
Polyethylene glycol (PEG) 3350	Disimpaction: 1–1.5 g/kg/day for three days Maintenance: 0.75 g/kg/day	Abdominal cramps and nausea
Lactulose	1–3 mL/kg/day in divided doses (3.3 g/5 mL)	Flatulence, abdominal cramps; less effective than PEG or paraffin oil
Liquid paraffin 50% (Parachoc)	12 months–6 years: 10–15 mL/day 7–12 years: 20 mL daily	Pneumonia if aspirated (children with reflux or unsafe swallow are at risk)
Stimulants
Senna	2–6 years: 2.5–7.5 mL/day 6–12 years: 5–15 mL/day Syrup – 7.5 g/5 mL Tablet – 1 tablet = 7.5 mg
Bisacodyl	4–18 years: 5–20 mg/day oral 2–18 years: 5–10 mg rectally once per day
Picosulfate	1 month – 4 years: 2.5–10 mg/day 4–18 years: 2.5–20 mg once per day

• Dis-impaction if severe

1. treatment of constipation is not effective if faecal impaction is not treated. 
2. Disimpaction dose for children is 1–1.5 g/kg/day of PEG for 3–6 day 
3. Review ongoing need on day 4

• In infants aged <1 month: 

• faecal impaction is rare and may be related to an underlying cause such as Hirschsprung’s disease.
• Exclusively breastfed babies defaecate anywhere from five times per day to once a week, and a decrease in stooling may be normal or abnormal.
• Referral for rectal biopsy to a tertiary paediatric facility should be considered if there is a clear history of not passing meconium with the first 48 hours of life or of ongoing thin, strip-like stools.
• Consider referral: To allied health – OT/continence physio if >4. Paeds if medication dependent after 6 months