Constipation Flashcards
Define constipation
The infrequent passage of dry, hardened faeces often accompanied by strain or pain and bleeding associated with hard stools
How does constipation present?
- Abdominal pain - waxes and wanes with passage of stool
- Overflow soiling
- Dehydration
- Decreased fluid intake
- Painful anal fissure
- Problems with toilet training
- Refusal
- Anxieties about opening bowels at school or in unfamiliar toilets
*3-8 = precipitating factors
How will the child appear on exam?
- Well child
- Normal growth
- Abdomen SNT
- Back and perianal area = normal position and appearance
- Soft faecal mass may be palpable in abdomen
List the primary underlying causes of constipation
- Hirschsprung disease
- Lower spinal cord problems
- Anorectal abnormalities
- Hypothyroidism
- Coeliac disease
- Hypercalcaemia
List the red flag symptoms/signs
- Failure to pass meconium in first 24hrs of life (Hirschsprung)
- Faltering growth/growth failure (hypothyroidism, coeliac, other)
- Gross abdominal distension (Hirschsprung, other GI dysmotility)
- Abnormal lower limb neurology or deformity (lumbosacral pathology)
- Sacral dimple (spina bifida occulta)
- Abnormal appearance/position/patency of anus (abnormal anorectal anatomy)
- Perianal bruising or multiple fissures (sexual abuse)
- Perianal fistulae, abscesses or fissures (perianal Crohn’s disease)
How do we manage long standing constipation?
- Disimpaction regime = polyethylene glycol 3350+electrolytes +/-stimulant laxative
- Explain to parents that soiling is involuntary
- Disimpaction followed by maintenance dose that is gradually decreased over a period of at least 6mths
- Dietary interventions = balanced dieat and increase fluid
- Behavioural interventions = sit on toilet after every meal to utilise physiologic gastrocolic reflex; can also make bathroom more inviting place
- Occasionally will need surgical evacuation under GA
- Relapse is common - treat early and aggressively
- Most common reason for treatment failure is underuse
Define Hirschsprung’s disease
Absence of ganglion cells from the myenteric and submucosal plexuses of part of the large bowel results in a narrow, contracted segment which extends from rectum for variable distance
How does Hirschsprung’s disease present?
- During neonatal period
- Failure to pass meconium in first 24hrs of life
- Abdominal distension
- Bile stained vomiting
What is observed on rectal examination in Hirschsprung’s disease?
- Narrowed segment
2. Gush of liquid stool and flatus on withdrawal of finger
How can Hirschsprung’s disease present in later childhood?
- Chronic constipation
- Abdominal distension
- No soiling
- Growth failure
What investigations should be performed if HD is suspected?
- Suction rectal biopsy - absence of ganglion cells and presence of large, acetylcholinesterase positive nerve trunks
- Anorectal manometry
- Barium studies
*2-3 useful for surgery
How is HD managed?
Surgically:
- Initial colostomy followed by anastomosing normally innervated bowel to anus
