Gastroenterology

Question 1

What are normal stools in different ages?

Answer 1

Infants- 4 stools per day in first week of life, falls to 2 stools per day by 1 year of age
Breasted infants- may not pass stool for several days and be entirely healthy
After 1 year of age- daily bowel action

Question 2

How does constipation present?

Answer 2

infrequent passage of dry, hardened faeces often accompanied by straining or pain and bleeding associated with hard stools
Abdominal pain whcih waxes and wanes
Possible overflow soiling
May be precipitated by dehydration or reduced fluid intake
anal fissure causing pain

Question 3

What could constipation be caused by in older children?

Answer 3

problems with toilet training, refusal and anxieties about opening bowels at school or in unfamiliar toilets

Question 4

What is seen on examination in constipation?

Answer 4

A well child whose growth is normal
• Abdomen is soft and any distension is normal for age
• Back and perianal area are normal in appearance and position
• A soft faecal mass may sometimes be palpable in lower abdomen, but is not
necessary for the diagnosis
• Do NOT perform PR: it may sometimes be considered by a paediatric specialist to
help identify anatomical abnormalities or Hirschsprung disease

Question 5

What are the causes of constipation?

Answer 5

after an acute febrile illness- usually resolves spontaneously or with use of maintenance laxative therapy and extra fluids
Underlying conditions:
o Hirschsprung disease (failure to pass meconium in first 24hr of life)
o Lower spinal cord problems
 o Anorectal abnormalities
o Hypothyroidism
o Coeliac disease
o Hypercalcaemia

Question 6

What are some signs which indicate an underlying cause of constipation?

Answer 6

Faltering growth/growth failure: hypothyroidism, coeliac disease, other causes
Gross abdominal distension: Hirschsprung disease or other GI dysmotility
Abnormal lower limb neurology or deformity (e.g. talipes):lumbosacral pathology
Sacral dimple above natal cleft, hairy patch over the spine: spina bifida occulta
Abnormal appearance/position/patency of anus: abnormal anorectal anatomy

Question 7

What occurs with long standing constipation?

Answer 7

Rectum becomes over distended, with a subsequent loss of feeling the need to
defecate
• Involuntary soiling may occur as contractions of full rectum inhibit the internal
sphincter, leading to overflow

Question 8

What is the management for constipation?

Answer 8

Evacuate the overloaded rectum completely
disimpaction regimen of stool softeners, initially with a macrogol laxative (or an osmotic laxative such as lactulose if that is not tolerated)
An escalating dose regimen is administered over 1-2 weeks or until impaction resolves

Question 9

What is the management for constipation if the first line is ineffective?

Answer 9

A stimulant laxative (e.g. Senna or sodium picosulphate)
may also be required
o Disimpaction must be followed by maintenance treatment to ensure
ongoing regular, pain-free defecation. Polyethylene glycol is generally the treatment of choice. The dose should be gradually reduced over a period of months
Child encouraged to sit on the toilet after mealtimes to utilise physiological gastrocolic reflex
Occasionally enema or manual evacuation under anaesthetic if severe faecal retention

Question 10

What is Hirschsprung disease?

Answer 10

absence of ganglion cells from the myenteric and submucosal plexuses of part of the large bowel, resulting in a narrow, contracted segment

Question 11

Where is Hirschsprung disease located?

Answer 11

abnormal bowel extends from the rectum for a variable distance proximally, ending in a normally innervated, dilated colon. 1 in 5000 live births affected, with ~10-20% of all cases familial.
In 75% of cases the lesion is confined to the recto sigmoid, but in the 10% entire colon is involved

Question 12

How does Hirschsprung disease present?

Answer 12

Intestinal obstruction shown as failure to pass meconium within the first 24h of life
• Abdominal distension
• Bile-stained vomiting
Occasionally present with life-threatening Hirschsprung enterocolitis during first few weeks of life

Question 13

How does Hirschsprung disease present in later childhood?

Answer 13

Chronic, usually profound constipation with/without soiling
• Associated abdominal distension
• Growth failure

Question 14

What is seen on examination in Hirschsprung disease?

Answer 14

PR may reveal a narrowed segment + withdrawal of the examining finger often
releases a gush of liquid stool and flatus. Temporary improvement in the obstruction following dilatation by PR may lead to delayed diagnosis

Question 15

How is a diagnosis of Hirschsprung disease made?

Answer 15

demonstrating the absence of ganglion cells, together with presence of
large, acetylcholinesterase-positive nerve trunks on a suction rectal biopsy.
• Anorectal manometry or barium studies may be useful in giving surgeons an idea of
the length of aganglionic segment, but are unreliable for diagnostic purposes

Question 16

What is the management for Hirschsprung disease?

Answer 16

Surgical colostomy followed by anastomosing normally innervated bowel to the anus

Question 17

What is encopresis?

Answer 17

medical term for a toilet trained child (>4yrs) soiling their clothes- can be classified by DSM as with constipation and overflow or without

Question 18

What is functional encopresis?

Answer 18

a rare form and is thought to be more psychological in nature- includes never being toilet trained, toilet phobia, manipulative soiling or IBS

Question 19

What is Hirschsprung enterocolitis?

Answer 19

Usually presents during first few weeks of life- due to C. diff
illness characterised by abdominal distension, bloody watery diarrhoea, circulatory collapse and septicaemia- mortality is 10%

Question 20

What is the 3 staged procedure used for the surgical management of Hirschsprung?

Answer 20

o Defunctioning colostomy, with multiple biopsies to confirm the site of the transition zone
o Pull-through procedure to bring ganglionic bowel down to the anus
o Closure of colostomy