Functional Constipation

Question 1

How would you define constipation?

Answer 1

• infrequent defecation, painful defecation, or both

Question 2

What are the features of chronic constipation?

Answer 2

2 or more of the following, present for 8 weeks

• Fewer than three bowel movements per week.
• More than one episode of faecal incontinence per week.
• Either palpable stools in the abdomen, or large stools palpable rectally.
• Passing stools so large they block the toilet.
• Retentive posturing and withholding behaviours.
• Painful defecation

Question 3

What is pelvic floor dyssynergia?

Answer 3

• inability to relax the pelvic floor when attempting to defecate

Question 4

What are the 2 types of faecal incontinence?

Answer 4

• Organic faecal incontinence - faecal incontinence resulting from organic disease
• Functional faecal incontinence - faecal incontinence without organic disease:
  
  • Constipation-associated faecal incontinence.
  • Non-retentive faecal incontinence -

Question 5

What children group is constipation commonly seen in?

Answer 5

• Infants at weaning
• Toddlers acquiring toilet skills
• School-age

Question 6

Constipation in children can be associated with what other factors?

Answer 6

• problems with toilet training
• psychological problems
• neurodevelopmental disorders
• autism
• major life events

Question 7

What questions would you ask the parents of a child with constipation?

Answer 7

• The frequency of defecation.
• Consistency of stools
• Episodes of faecal incontinence.
• Pain on defecation.
• Whether stools block the toilet.
• Any associated behaviour

Question 8

What examination would you perform for constipation?

Answer 8

• Palpation of the abdomen for faecal mass.
• Inspection for anal stenosis or ectopia.
• Looking for sacral abnormalities

Question 9

What are the causes of constipation?

Answer 9

• Anorectal malformations - DRE
• Hirschsprung’s disease - rectal biopsy, barium enema
• Anal fissure
• Pelvic floor dyssynergia - Anorectal manometry
• Spinal cord problems - MRI
• Neurenteric problems - colonic motility test
• Hypothyroidism - TFT
• Coeliac disease
• Hypocalcaemia - calcium test
• Cystic fibrosis - sweat test
• Cow’s milk allergy - elimination test

Question 10

How would you diagnose constipation in under 1 yo?

Answer 10

• Less than three complete stools per week
• Large hard stool or ‘rabbit droppings’.
• Symptoms associated with defecation: distress on passing stool, bleeding with hard stool or straining.
• Past history of constipation.
• Previous or current anal fissure

Question 11

How would you diagnose constipation in above 1 yo?

Answer 11

• Overflow soiling (the child may be unaware of passing loose, smelly stools, which may be thick and sticky, or dry and flaky).
• Large stools, big enough to block the toilet
• Poor appetite that improves with passage of a large stool.
• Abdominal pain which waxes and wanes with passage of stool.
• Retentive posturing - eg, on tiptoes, straight-legged, and with an arched back.
• Straining, painful bowel movements, and/or anal pain

Question 12

How would you Mx functional constipation conservatively?

Answer 12

• reassure that tx may take months
• fibre, fluids, exercise
• Assess for faecal impaction

Question 13

What are the pharmacological options for functional constipation?

Answer 13

Disimpaction

• Polyethylene Glycol (PEG) + Movicol (first line)
• Sodium Senna +/- lactulose or docusate

Add these drugs if ineffective after 2 weeks

• sodium senna - >1m old
• docusate >6m old
• bisacodyl suppositories >2years old

Maintenance therapy

• use bowel charts
• fluid and fibre intake
• regular laxatives