GASTROINTESTINAL SYSTEM
Department of pediatrics
Development of GIT:
• A gut tube can be subdivided into 3 : foregut ,
midgut , hindgut
• The digestion sys. develops from the 3 parts, the
hindgut gives rise to the GI structure from the
esophagus to the 2nd part of the duodenum . liver
and pancreas develop as out growth from the
hindgut .
• The midgut gives rise to the structures from the 2nd
part of duodenum to the first 2/3 of the large
intestine the hindgut then given rise to the
structure from the remaining large intestine to the
rectum .
• The primitive gut begin to develop as an
endodermally lined tube surrounded by mesoderm
which envelopes the gut and form as dorsal
mesentery
• The stomach develops from the hindgut starting at
the 4th week it begin as a dilatation of the gut tube
and during development it shifts position by both
moving caudally and rotating
• The anterior surface and the right side of the gut
tube will become the posterior surfaces of the
stomach , the caudal movement of the stomach
results in pyloric partum of the stomach lying at
the same level as the body of the stomach .
• The first part of the duodenum and the beginning
of the 2nd part are derived from the foregut , the
remaining duodenum and ilium will be derived
from the midgut , the appendix , cecum ,
ascending , colon and the 2/9of trans colon are
derived from the midgut the last 1/3 of transcolon
and the descending and sigmoid are derived from
the hindgut , the midgut can be divided into 2
portion:
• 1-cephalic of midgut extends from the
duodenum to the yolk sac , the cephalic will
then form the lower duodenum and the upper
ilium.
• 2-caudal will form the lower ilium . appendix ,
cecum , ascending colon . 2/3 of trans colon.
• Mesentery is the a splanchnic mesoderm that connects
the primitive gut to the body wall.
• During development ventral mesentery exists only
between the liver –stomach
liver-duodenum.
• The ventral mesentery goes on to form the lesser
omentum (liver-stomach) and the falciform ligament at
liver and anterior body wall.
• The dorsal mesentery surrounds the rest of primitive
gut in the region of the stomach the dorsal meso
develops into spleen renal and gastrospleenal lig.
• The dorsal mesentery persists and develops
into mesenteric produced between small
intestine and post . body wall finally the meso
of the colon develops into the trans
mesocolon
• The development of the mesenteries and
location of these structures are largely
dictated by notation of the gut and other
movement of development stomach and GIT .
• Organs that were originally in the dorsal mesentery
came to retroperitoneal position are part of
duodenum, the blood supply to the GI structure
Langley along with developed from the foregut it
receives blood supply from colic a , if from the
midgut blood supply from sup mesenteric a.
• Pancreas:
•the pancreas develops as organ growth of duodenum
, it develops as to pancreatic ( dorsal , ventral ).
• Liver :
• develops from diverticulum , the portion of the
diverticulum to duodenum develops into hepatic
duct , bile duct and gall bladder .
• the remaining portion becomes the epithelial plates
of the liver
• the vital line veins become incorporated and give
rise to hepatic sinusoids.
GIT complaints are common pediatric
problem central history and physical
examination are necessary to determine
the symptoms are due to primary GI
illness or to systemic disease and
manifestation that are associated.
Techniques of examination :
-inspection: skin , these include color , scars ,
dilated veins of hepatic , destruction ,
inflammation , hernia , abdomen ( flat rounded ,
protuberant , symmetrical ) visible organs liver or
spleen that has descended below the ribs cage ,
peristalsis , observe for several minutes in a
suspicion of OBS , peristalsis may be visible
normally in very thin people , pulsation ( increase
pressure , increase aortic pulsation , epigastrium
can be visible )
auscultation:
listen bowel sounds , frequency characteristics ,
normal sound consist of click , the frequency has
been estimated 5-35/min . the bowel sound may
be altered on diarrhea , peritonitis.
percussion :the liver measure vertical high of
the liver , liver dullness of the R midclavicular line
, the liver dullness is decrease when the liver is
small , it may also decrease when free air is
present below the diaphragm , enlargement of
the liver in hepatitis , CHF .
in suspicion of splenomegaly to try 2 :
1- percusion lower its the if ant axillary line thus area
is usually tympanic then ask the patient to take deep
breath and to percuss again normally the percussion
remains tympanic
2- percusion in several direction from tympanic
toward the estimated area of splenic dullness so that
you can outline its edges
can be determine also the size , impaired by varying
contents of stomach and colon but may be suggest
splenomegaly even before the organ becomes palpate
-palpation: superficial palpation is specially
helpful identifies the muscular resistance of the
abdomen.
deep palpation :is usually required to
determine abdominal masses , location , size ,
shape , tenderness , pulsation
LIVER :
palpation of liver is done by placing the fingers
supporting 4-12 ribs , remind the patient to relax
. to place the R hand on the patient abdomen to
ask the patient for deep breath to describe the
liver edges and measure them .
SPLEEN:
LF hand reach over and around the patient to
support and press forward the lower IF ribs cage,
the R hand below the costal margin press in
toward the spleen . Ask the patient to take deep
breath and try to feel the edges of the spleen.
tenderness , splenic can measure the distance
between lower points and LF costal margin ,in
children the liver is easily palpated in most
children the edge is normally felt 1-2cm below
costal margin sharp.
THE SIZE OF THE LIVER :
AGE
MALE
female
5m
2.4
2.8
1y
2.8
3.1
5y
4.8
4.5
10y
6.1
5.4
16y
7.1
6.0
adults
7.7
6.3
ACUTE ABDOMINAL PAIN
In children acute gastroenteritis is one the most
common cause of acute abdominal pain , in infants
less than 2 years , ( trauma , UT infection ) in between
2-5 ( lower lobe pneumonia , UT infection ) in older
and adolescents appendicitis is more common may be
difficult to distinguish from gastroenteritis in
adolescent pelvic inflammatory disease .
CHRONIC ABDOMINAL PAIN
Its defined as 3 or more episodes of pain , sever pain
affects activities for ex in irritable bowel syndrome
many associated symptoms such as pallor , nausea
headache , diarrhea . sleep disturbances , are seen be
due to colic lactose intolerance , colic disease , tumors
in order children in lactose intolerance , IBO ,
esophagitis .
DIARRHEA:
MECHANISM
Defect
Stool
1
secretory
decrease absorption
watery , appear in E. coli , cholera .
2
osmotic
maldigestion ,
transport defect
Watery , acidic ,reduce in sub .
↑osmolarity appears in lactose def. ,
glucose , galactose .
3
increase motility decrease transit , stasis like stimulate gastro colic reflex
4
decreased
surface area
decrease functional
capacity
watery short bowel syndrome
5
mucosal
invasion
inflammation ,
decrease colic
reabsorption ,
↑motility
Blood appear in salmonella , shigella ,
eserina …
CONSTIPATION:
is defined as infrequent passage of hard dry stools , causes ,
non organic or functional.
organic include :
1-intestinal - stenosis
2-drugs- narcotics
3-metabolic dehydration , hypokalemia
4- neuromuscular
stool retention may be due to toilet training or pain in
defection and create in future retention of stool,
consequences intoxication , abdominal pain , UT infection.
 at term infants meconium shoulder be passed within the
first 24h of life failure to pass meconium suggest can
underlying disorder, frequency of bowel movement vary
greatly in the individual child among different children.
the breast fed infants produce stool every feeding but
many produce 1-2 time-day.
formula fed -produce daily but may be 2-3t day .
the range of normal for infant is 5 stool/day .
failure to defecate may be due to decrease peristalsis in
spinal cord defect.
VOMITING:
a forced ejection of gastric content is often preceded by
nausea is due to the coordination of gastric atony except
pyloric stenosis , relaxation of gastroesophageal junction
increase intragastric pressure from abdominal wall
contraction
regurgitation a passing nonforce of gastric content due to
reflex through a relaxed lower esophageal sphincter .
The differential diagnosis of vomiting should be
appreciated by considering age specific disease during
neonatal period GI obstruction is often causes of
regurgitation. gastroenteritis, overfeeding , gastro
esophageal reflux, food allergy , milk protein intolerance.
In children and adolescent vomiting is caused by
gastroenteritis , systemic infection , appendicitis , IBO .
GI HEMORRAHAGE
Hemorrhage may occur of any location in GIT, hematemesis
, the blood emesis results hemoprofused bleeding proximal
to the ligament treitz , less sever appear GI bleeding results
in a coffee-ground .
melena: refer to soft usually black or dark color stool it is
suggestive of bleeding from the oropharynx to the colon ,
stasis of blood in the R colon , bleeding lesion in that area
may appear as melena.
Hematochezia : refer to bright red or marrow colored stools
, typically the lesion is colored .
GI bleeding:
defined as significant blood loss in the absence disernable
change in the color , loss many produce iron deficiency ,
anemia .
differential diagnosis of GI hemorrhage based on a carful
history and physical examination of the child site of
bleeding.
MANEGMENT:
1-correct hypovolemia
2-correct anemia
3-stop bleeding
4-prevent recurrence
5-diagnose the cause
6-applay specific therapy.