Paeds - GI

Question 1

where is the pyloric sphincter?

Answer 1

ring of smooth muscle between stomach and duodenum

Question 2

what is pyloric stenosis?

Answer 2

hypertrophy of the pyloric sphincter causing narrowing which prevents food traveling to duodenum as normal

Question 3

classical features of pyloric stenosis?

Answer 3

projectile vomiting
usually presents in first few weeks of life
hungry baby
thin, pale and failing to thrive

Question 4

what causes projectile vomiting in pyloric stenosis?

Answer 4

increasingly powerful peristalsis tries to push food through stenosis
eventually becomes so powerful that is ejects food into the oesophagus and out of the mouth

Question 5

what might be seen on examination in pyloric stenosis if examined after feeding?

Answer 5

peristalsis might be seen in abdomen

firm round mass might be felt in upper abdomen (feels like big olive) caused by hypertrophied sphincter

Question 6

blood gases in pyloric stenosis?

Answer 6

metabolic alkalosis (due to vomiting)
low chloride

Question 7

how is pyloric stenosis diagnosed?

Answer 7

abdo US showing thickened sphincter

Question 8

how is pyloric stenosis managed?

Answer 8

laparoscopic pylorotomy ("ramstedt's operation)
incision made in smooth muscle of pylorus to widen canal

Question 9

what is biliary atresia?

Answer 9

congenital condition where section of bile duct is either narrowed or absent
results in cholestasis as bile cant be transported from liver to bowel

Question 10

what type of bilirubin builds up in biliary atresia?

Answer 10

conjugated (as its obstructed after the liver)

Question 11

how does biliary atresia present?

Answer 11

presents shortly after birth

jaundice (suspect biliary atresia in babies with persistent jaundice for >14 days or >21 days in premature babies)

Question 12

initial investigation in biliary atresia?

Answer 12

measure conjugated and unconjugated bilirubin (high conjugated bilirubin suggests obstruction after the liver)

Question 13

what can cause jaundice in neonate?

Answer 13

many benign causes such as breast milk jaundice

Question 14

how is biliary atresia managed>

Answer 14

surgery (kasai portoenterostomy)

involves attaching section of small intestine to the opening of the liver where bile duct would normally attach

Question 15

how successful is surgery in biliary atresia?

Answer 15

somewhat successful

clears jaundice and prolongs survival but often need a full liver transplant at some point

Question 16

what is hirschsprungs disease?

Answer 16

congenital condition where nerve cells of the myenteric plexus are absent in distal bowel and rectum

Question 17

what is the myenteric plexus?

Answer 17

forms enteric nervous system (brain of the gut)
AKA auerbachs plexus
runs all the way along the bowel in bowel wall
responsible for peristalsis of large bowel

Question 18

key pathophysiology of hirschsprungs disease?

Answer 18

absence of parasympathetic ganglion cells in part of myenteric plexus supplying distal colon and rectum

Question 19

how much of bowel isnt innervated in hirschsprungs?

Answer 19

varies between patients
can range from small area up to entire colon
(called total colonic aganglionosis)

Question 20

what happens to part of bowel without innervation in hirschsprungs?

Answer 20

section does not relax causing it to become totally constricted
leads to loss of movement of faeces and bowel obstruction
bowel proximal to constriction becomes distended and full

Question 21

what causes hirschsprungs?

Answer 21

number of associated genes

family history greatly increases risk

Question 22

hirschsprungs usually occurs in isolation but what other syndromes are associated with hirschsprungs?

Answer 22

downs
neurofibromatosis
waddenburg
MEN2

Question 23

how does hirschsprungs present?

Answer 23

presentation and age of presentation varies depending on severity
can present with acute bowel obstruction shortly after birth or more gradual symptoms such as
- delayed meconium (>24 hrs)
- chronic constipation since birth
- abdo pain and distension
- vomiting
- poor weight gain and failure to thrive

Question 24

what complications can occur from hirschsprungs?

Answer 24

hirschsprung-associated enterocolitis (HAEC)

Question 25

what is HAEC?

Answer 25

inflammation and obstruction of intestine occurring in around 20% of neonates with hirschsprungs

Question 26

how does HAEC present?

Answer 26

2-4 weeks following birth

fever, abdo distension, diarrhoea (often bloody) and features of sepsis

Question 27

risks associated with HAEC?

Answer 27

toxic megacolon

bowel perforation

Question 28

how is HAEC managed?

Answer 28

antibiotics
fluid resus
decompression of obstructed bowel

Question 29

how is hirschsprungs diagnosed?

Answer 29

abdo X ray can show obstruction

rectal biopsy confirms diagnosis (shows absence of ganglionic cells)

Question 30

definitive management of hirschsprungs?

Answer 30

surgical removal of aganlgionic (non-innervated) section of bowel
most patients have normal life after but can have long term bowel disturbance

Question 31

what is intussusception?

Answer 31

condition where bowel telescopes into itself

thickens the overall size of the bowel and narrows lumen at folded area leading to obstruction

Question 32

who does intussusception most commonly occur in?

Answer 32

boys

age 6 months - 2 years

Question 33

what is intussusception associated with?

Answer 33

concurrent viral illness
henoch schonlein purpura
CF
intestinal polyps
meckel diverticulum

Question 34

how does intussusception present?

Answer 34

"redcurrant jelly stool" = buzzword
severe colicky abdo pain
pale lethargic unwell child
RUQ mass on palpation ("sausage shaped")
vomiting
intestinal obstruction

Question 35

typical child with intussusception?

Answer 35

recent viral URTI
features of obstruction
palpable sausage shaped mass in RUQ
redcurrant jelly stool

Question 36

how is intussusception diagnosed?

Answer 36

US = initial investigation of choice

contrast enema can be used

Question 37

how is intussusception managed?

Answer 37

therapeutic enemas can be used to reduce it (contrast, water or air are pumped into colon to force folded part out of bowel and into normal position)
surgical reduction might be needed if enema doesnt work
surgical resection needed if bowel becomes gangrenous or perforated

Question 38

possible complications of intussusception?

Answer 38

obstruction
perforation
gangrenous bowel

Question 39

what is the most common congenital small bowel abnormality?

Answer 39

meckels diverticulum

Question 40

what is meckel’s diverticulum?

Answer 40

true diverticulum resulting from failure of the viteline duct to obliterate during 5th week of foetal development (embryological remnant)

Question 41

how might meckel’s diverticulum present?

Answer 41

often asymptomatic
usually present before age 2 
passage of bright red blood (rectal) - GI bleed is most common presenting feature
constipation 
nausea and vomiting
abdo pain and cramping

Question 42

what can meckels diverticulum cause?

Answer 42

can cause bleeding, intussusception, obstruction, inflammation or perforation

Question 43

investigations in meckels?

Answer 43

technetium-99m pertechnetate scan (“meckel’s scan”) = most useful
abdo X ray (not great)
colonoscopy

Question 44

how is meckels managed?

Answer 44

only if symptomatic/problematic

can have surgery to remove section of bowel with diverticulum