Gastroenterology: Constipation Flashcards
Is constipation a common reason for consultation?
Yes, very common
Is the ‘normal’ frequency of defecation highly variable?
Yes and varies with age
In the first week of life what is the average number of stools per day?
4
By 1 year of age, what is the average number of stools per day?
2 per day
By 3 years old what is the average number of stools per day?
1
Breastfed infants may not pass stools for several days and be entirely healthy. True or false?
True
In children less than 1, a diagnosis of constipation is suggested by 2 or more of the following…
Stool pattern:
- fewer than 3 complete stools per week (type 3 or 4)
- hard, large stool
- rabbit droppings (type 1)
Symptoms associated with defecation:
- distress on passing stool
- bleeding associated with hard stool
- straining
History:
- previous episode(s) of constipation
- previous of current anal fissure
In children over 1, a diagnosis of constipation is suggested by 2 or more of…
Stool pattern:
- fewer than 3 complete stools per week (type 3 or 4)
- overflow soiling
- rabbit droppings (type 1)
- large, infrequent stools that can block the toilet
Symptoms associated with defecation:
- poor appetite that improves with passage of large stool
- waxing and waning of abdominal pain with passage of stool
- evidence of retentive posturing
- straining
- anal pain
History:
- previous episode(s) of constipation
- previous or current anal fissure
- painful bowel movements and bleeding associated with hard stools
What is retentive posturing?
Straight legged, tiptoed, back arching posture
Do the majority of children have no identifiable cause?
Yes
What causes are there?
Idiopathic Dehydration Anal fissure causing pain Low fibre diet Problems with toilet training Refusal and anxiety about opening bowels at school or unfamiliar environment Hypothyroidism Hirschsprung’s disease Hypercalcaemia Coeliac disease Crohn’s disease Spina bifida occulta Lumbosacral pathology Abnormal anorectal anatomy Sexual abuse
What red flag symptoms or signs are there?
Failure to pass meconium within 24 hours of life (Hirschsprung)
Faltering growth (hypothyroidism, coeliac)
Gross abdominal distension (Hirschsprung)
Abnormal lower limb neurology or deformity
Sacral dimple above natal cleft, over the spine - naevus, hairy patch, central pit, discoloured skin (spina bifida occulta)
Abnormal appearance/position/patency of anus
Perianal bruising or multiple fissures (sexual abuse)
Perianal fistulae, abscesses, fissures (Crohn’s)
What does examination usually reveal?
A well child Normal growth Abdomen is soft Any distension normal for age Back and perianal area normal in appearance and position
A soft faecal mass may sometimes be palpable in the lower abdomen. True or false?
True - but not necessary for diagnosis
Is a primary underlying cause for the constipation rare?
Yes, but underlying conditions should be considered
Should a DRE be performed?
No - may be done by paediatric specialist to identify anatomical abnormalities or Hirschsprung’s disease
Are investigations usually required for diagnosis?
Usually not - carried out as indicated by history or clinical findings
How is constipation arising acutely in young children e.g after acute febrile illness, managed?
Usually resolves spontaneously
Or with the use of maintenance laxative therapy and extra fluids
Prior to starting treatment, what should the child be assessed for?
Faecal impaction
- symptoms of severe constipation
- overflow soiling
- faecal mass palpable in abdomen
What can happen in long standing constipation?
The rectum becomes over distended, with a subsequent loss of feeling the need to defecate.
Involuntary soiling may occur as contractions of the full rectum inhibit the internal sphincter, leading to overflow
Does long-standing constipation often need MDT approach?
Yes
Secondary behavioural problems are common
Can recovery of normal recall size and sensation be achieved?
Yes but may take a long time
- disimpaction followed by maintenance treatment
How is faecal impaction managed?
Stool softeners - initially with a macrogol laxative e.g polyethylene glycol 3350 + electrolytes (movicol paediatric plain)
An escalated dose regime administered over 1-2 weeks until impaction resolves
If unsuccessful: a stimulant laxative e.g senna or sodium picosulphate may also be required
If polyethylene glycol + electrolytes not tolerated, an osmotic laxative e.g lactulose can be substituted
What must disimpaction be followed by?
Maintenance treatment - to ensure ongoing regular, pain free defecation
What is generally the treatment of choice for maintenance?
Polyethylene glycol with or without stimulant laxative
Dose should be gradually reduced over a period of months in response to improvement in stool consistency and frequency
Are dietary interventions alone of benefit?
No, little or no benefit. Although child should receive sufficient fluid and balanced diet.
Addition of extra fibre is not helpful - may make stools larger and more difficult to pass.
Child should be encouraged to sit on the toilet after mealtimes to utilise the physiological gastrocolic reflex and improve likelihood of success
The outcome is more likely to be successful if…
Child engaged in treatment process - behavioural interventions useful e.g star chart to record and reward progress
Encouragement by family and health professionals essential
Is relapse common?
Yes
What is the mainstay of treatment?
The early, aggressive and prolonged use of laxative medication in a dose that allows the passage of large, soft stool at least once per day
Is the use of laxatives safe?
Yes even in the long term
What is the commonest reason for treatment failure?
Under use of laxatives
If the faecal retention is so severe, what can be done?
Enema or manual evacuation under anaesthetic
How should constipation be managed in infants not yet weaned?
Bottle fed: give extra water between feeds, try gentle abdominal massage and bicycling legs
Breast fed: constipation is unusual and organic causes should be considered
