Constipation

Question 1

Define constipation

Answer 1

Decrease in the frequency of bowel movements ± passing of large, hard stools ± straining ± pain

2 or more of the following features:
- Infrequent passage (<3 complete stools per week)
- Hard, large stool
- “Rabbit dropping” stool
- Overflow soiling

Question 2

What is chronic constipation

Answer 2

constipation > 8 weeks

Question 3

What is the normal frequency of defecation in children (breastfed, 1 year old, 4 year old)

Answer 3

Breastfed infants: ≥4x a day, but may not pass stool for several days
1yo: 2x a day
4yo: 3 stools per day - 3 stools per week (adult stool pattern)

Question 4

What are the causes of acute constipation

Answer 4

Dehydration/fluid depletion (Following vomiting, hot weather, febrile illness)
Inadequate dietary fibre intake
Bowel obstruction
Side effect of medications e.g. sedating antihistamines, opioids

Question 5

What are the causes of chronic constipation

Answer 5

Functional constipation
GI: Hirschsprung’s disease, coeliac disease
CMPA
Endo: Hypothyroidism
Rectoanal: Anal stenosis, Abnormal anorectal anatomy, Perianal Crohn’s disease
Neurological or spinal cord abnormality
Spina bifida occulta
Breast-fed babies (can be normal for the baby to pass only one stool in 7 days if exclusively breastfed)
Withholding of stool to avoid distraction from play
Problems with toilet training
Anxiety about opening bowels at schools or in unpleasant or unfamiliar toilets

Question 6

What are the risk factors for constipation

Answer 6

FHx constipation
Immobility: physically inactive or impaired mobility e.g. CP, neurodevelopmental disorder

Question 7

What is the epidemiology for constipation

Answer 7

Seen most often between 2-4 years of age
Prevalence is around 10-20%

Question 8

What are the symptoms of constipation

Answer 8

Constipation (<3 stools a week (unless exclusively breastfed))
- Stools typically semi-soft (3 or 4 on Bristol Stool Form scale)
- Hard, large stool, may block the toilet
- Rabbit droppings-like stool
Soiling of clothes (loose, smelly, passed without awareness)
Difficulty defecating
- Distress or pain
- Bleeding with hard stool
- Straining
- Retentive posturing (straight-legged, tiptoes, arched back)
Poor appetite, improves with passage of stool
Abdominal pain (waxing and waning)
Anal pain

Question 9

What are the signs of constipation on examination

Answer 9

Height and weight: ?failure to thrive (Hirschsprung’s, hypothyroidism, coeliac)

General
Precipitant dehydration: sunken eyes, poor skin turgor, dry mucous membranes, prolonged CRT
- “retentitive posturing”: straight-legged, tiptoes, arched back

Abdominal exam: abdominal mass, often LLQ

Anorectal: normal OR anal fissures, hard stools, ?signs of sexual abuse, perianal infection (erythema, local oedema)

Question 10

What investigations should be done for constipation

Answer 10

Investigations are not usually required

AXR: may show faecal impaction

Question 11

What are the red flags for constipation presentation

Answer 11

Constipation from birth on during the first few weeks of life
Delay in meconium passage
Abdominal distension with vomiting
Ribbon stool pattern
FHx Hirschsprung’s disease
Leg weakness or motor delay
Abnormal anal appearance (fistulae/bruising/fissures/tight/patulous)
Absent anal wink (fails to contract when the skin around is stroked)
Abnormalities in the lumbosacral and gluteal regions

Question 12

What are the amber flags for constipation presentation

Answer 12

Faltering growth/developmental delay/wellbeing concerns
Symptom onset with cow’s milk
Concerns about child maltreatment

Question 13

What is the management for constipation

Answer 13

• Reassurance: underlying causes have been excluded
• Advice on diet and oral fluids & toileting habits
• Pharmacological treatment: macrogol (movicol paediatric plain)

+ regular follow up

Question 14

What advice should be given for diet and fluid intake in constipation

Answer 14

Eat food with high fibre content e.g. fruit, vegetables, high-fibre bread, baked beans, wholegrain breakfast cereals
Normal daily physical activity that is tailored to developmental stage and ability
3/4 of the daily fluid requirement is obtained from water in drinks, and higher intakes are required for those in hot environments or are obese

Question 15

What is the recommended fluid intake for children 0-6 months, 7-12 months, 1-3 years, 4-8 years, 9-13 years, and 14-18 years

Answer 15

0-6 months: 700mL
7-12 months: 800mL
1-3 years: 900mL from drinks
4-8 years: 1200mL from drinks
9-13 years: Boys: 1800mL from drinks | Girls: 1600mL from drinks
14-18 years: Boys: 2600mL from drinks | Girls: 1800mL from drinks

Question 16

What advice should be given about toileting habits in constipation

Answer 16

Scheduled toileting - encourages the child to try and open their bowels at pre-planned intervals or activities such as after each meal of five minutes
Bowel habit diary to track frequency and consistency e.g. ERIC Toilet Tool Wallchart
Use of Star charts

Question 17

What is the pharmacological treatment for constipation

Answer 17

First line: Macrogol (Movicol® Paediatric Plain or Movicol®)
- Fruit squash may be added as it is not preferable to children
- Continue for at least several weeks after regular bowel movements are established (May take several months)
1-5yo: 1 sachet daily
>5yo: 2 sachets daily

Second line: Add Senna (stimulant laxative)

Question 18

What is the management for faecal impaction

Answer 18

1. Evacuate the overloaded rectum
   Warn parents that treating impaction may increase symptoms of soiling and pain worse initially and to ensure there is easy access to a toilet
   a. First line: Movicol Paediatric plain (Polyethylene glycol) - escalate dose over 1-2 weeks, once resolved gradually reduce over months
   <1yo: 1 sachet daily
   1-4: 2 sachet, increase in increments of 2 until 8 daily
   >5: 4 sachets, increase until 12 daily
   >12: 4 sachets, increase until 8 daily
   i. Alternative: lactulose (osmotic laxative)
   b. Second line (2 weeks: Senna, sodium picosulphate (stimulant laxatives)
2. Third line: NG large volume macrogol (Klean Prep)
3. Enemas or manual evacuation under anaesthetic

Question 19

What is the difference between osmotic and stimulant laxatives and give examples of each

Answer 19

Osmotic: increases the amount of fluid in the large bowel, softening the stool and stimulating peristalsis e.g. movicol, lactulose

Stimulant: stimualtes the colonic and rectal nerves to stimulate peristalsis e.g. senna, docusate, bisacodyl, sodium picosulphate

Question 20

What are the complications of constipation

Answer 20

Overflow diarrhoea and soiling (long-standing complications lead to overdistension of the rectum → loss of feeling to need to defecate + inhibition of the internal sphincter
Anal fissures (pain → stool withholding → stool hardening → constipation)
Haemorrhoids
Rectal prolapse
Megarectum
Volvulus
Distress for child and family, physical discomfort, missed school, poor school performance, social isolation

Question 21

What is the prognosis for constipation

Answer 21

More likely to become persistent if it develops in early infancy and the child has a FHx of constipation
Delay in treatment correlates with a longer duration of symptoms
Symptoms can become chronic in more than 1/3 of children
Around half of children recover with laxative use after 6-12 months