A 7 year old female is brought to the ED with a chief 
complaint of abdominal pain.  She vomited once and 
feels weak.   Emesis occurred about 1 hour after eating 
saimin (a local soup/noodle dish, also called ramen) 
from a neighborhood lunch/snack truck (a small mom 
and pop type business).  The pain is worse in the 
periumbilical region described as painful and somewhat 
intermittent.  Her mother stated that this happened to 
her in the past and they waited too long before coming 
in to the emergency room.  During this previous 
episode, she was given IV fluids at which point, her 
symptoms largely resolved and she went home.  Her 
mother didn't want her to suffer as much as she did the 
last time, so she was brought in early this time, despite 
only vomiting once.
     Exam VS T36.7,  HR 91,  RR 24, BP 140/81.  She is 
uncomfortable, but in no respiratory distress.  She is 
alert and cooperative.  Her oral mucosa is moist and 
her eyes are not sunken.  Neck supple.  Heart regular 
without murmurs.  Lungs clear.  Abdomen flat, soft, and 
non-tender.  Bowel sounds are active.  No masses are 
felt.  No hernias and no CVA tenderness.
     Laboratory studies were drawn and an IV infusion of 
Lactated Ringer's was started because this was 
indirectly requested by her mother in the description of 
her past experience.  Additionally, the patient seemed 
so disproportionately uncomfortable despite her benign 
exam findings and a history suggestive of food 
poisoning.
     Lab results CBC Hgb 15, Hct 45,  WBC 14,000 
without a left shift.  Na 144, K 3.2,  Cl 110,  Bicarb 22, 
glucose 169. The patient received a total of 400cc of 
Ringer's Lactate and a phenergan suppository while in 
the E.D.  At which time, her abdominal pain resolved.  
There was no further vomiting since her initial episode 
of emesis prior to arrival.  She was not retching and she 
was feeling much better.  She was sleeping and had to 
be awakened to go home.  She ambulated briefly but 
became grumpy after awakening and wanted her 
mother to carry her.   Her abdomen was non-tender.  
She was discharged with a diagnosis of  "Food 
Poisoning" with the usual vomiting instructions.  She 
was instructed to return if worse.  You might wonder 
why a patient who is ill for only an hour had blood tests 
and IV fluids.  Call it overkill or instinct.  Read on. . .
     Six hours after discharge from the E.D. the patient 
returns because she it still vomiting, has pain, and feels 
her abdomen is distended.  She has not had a bowel 
movement since a small one early in the morning 
before the onset of symptoms.  Her mother 
administered an enema with only fluid return.
     Exam VS T37.0, HR 166, RR 48, BP 88/57, oxygen 
saturation 97% in room air.  Her exam showed a 
distended abdomen, diffuse tenderness (more so 
periumbilical without rebound), no stool and no 
tenderness on rectal exam with a smear showing 
specks of heme positive material.   A repeat of her labs 
was done.  CBC WBC 21,500, 65 segs, 20 bands, Hgb 
12.4, Hct 36.4.  Na 142, K 3.1, Bicarb 17.  Shortly after 
arrival she vomited 800cc of yellow fluid.  An 
abdominal series was ordered.

View abdominal series.  Flat (supine) view.


Left lateral decubitus view.

     This series of radiographs shows a large distended 
loop in the RUQ.  There are other less dilated loops in 
the RLQ.  The remainder of the abdomen is relatively 
gasless.  The lateral decubitus view shows only a few 
small air fluid levels and the same distended loops.
     A surgical consultation was sought.  The patient 
received Ringers 500cc and was admitted to the 
hospital.  She was observed and continued to receive 
fluid support but became progressively worse.  She 
developed a fever and dropped her hemoglobin to 5.3.  
At surgery, approximately 24 hours after her initial 
presentation, she was found to have malrotation with a 
midgut volvulus.  The small bowel was infarcted and 
necrotic and required removal of her entire small 
intestine.
     In reviewing this case we see the initial presentation 
is entirely nonspecific.  However, the rapidity of change 
in the patient's vital signs, labs, and requirement for 
very aggressive fluid management point to the evolution 
of a serious problem.  The abdominal radiographs 
provided important information that could (should?) 
have been acted on sooner.  The distended loops and 
absence of gas in the other areas of the abdomen in 
conjunction with the clinical findings of abdominal 
distention and bilious vomiting should raise the 
suspicion of a bowel obstruction.  Unfortunately in 
pediatrics, the radiographic diagnosis of a bowel 
obstruction may not be very obvious.  The aim (aaiimm) 
of this case is to consider the following in the differential 
diagnosis of a bowel obstruction using the mnemonic 
A-A-I-I-M-M:
     Adhesions
     Appendicitis
     Intussusception
     Inguinal hernia
     Malrotation
     Miscellaneous (Meckel's, tumor, duplication, etc.)


View another abdominal series. 
Flat (supine) view.


Upright view.


     Comment on this abdominal series.  Can you reach 
a diagnosis?

     These radiographs show very little bowel gas.  
There is a small amount of gas on the left.  Otherwise, 
the only significant air filled loop that is seen, is located 
in the RUQ.  These findings are again non-specific, but 
they suggest the possibility of a bowel obstruction.  This 
patient turned out to have a malrotation.
     Malrotation of the intestine is the underlying 
abnormality which predisposes the bowel to volvulus 
(twisting) and subsequent ischemic necrosis.  The term 
"malrotation" refers to an occurrence in fetal 
development at the point where the bowel returns to the 
abdominal cavity.  After entering the midabdomen 
at 12 o'clock, the cecum rotates counterclockwise into 
the right lower quadrant at 7 o'clock.  The true 
significance of the rotation is not so much that the 
cecum must be in the right lower quadrant, but the fact 
that the mesentery, containing the superior mesenteric 
artery, goes with it.  The mesentery grows to fix the 
terminal ileum to the posterior abdominal wall.  This 
produces a fan of mesentery securing the small bowel 
from the upper midabdomen just behind the duodenum 
to the right lower quadrant.

View normal meseteric fixation.

     Note the broad fan of meseteric attachment of the 
small bowel making it difficult for a volvulus of the small 
bowel to occur.
     If the correct rotation does not occur, it is termed 
"malrotation".  This results in the failure of proper 
mesenteric development so that instead of a broad fan 
of mesenteric attachment, the entire midgut is attached 
to the posterior abdominal wall by a short, narrow stalk 
in the region of the duodenum.  There may also be 
bands crossing the duodenum (Ladd's Bands) which 
can cause duodenal obstruction.

View malrotation and Ladd's bands.

     Note the mesenteric attachment of the cecum.  This 
narrow stalk is more prone to volvulus.  Additionally, 
this stalk (Ladd's bands) is capable of compressing the 
duodenum and obstructing it.
     In a malrotation, many meters of intestine are free to 
twist around this stalk, which, since it contains the 
superior mesenteric artery, is vulnerable to 
strangulation and ischemic necrosis.  The occurrence of 
this twisting and strangulation results in the surgical 
emergency called midgut volvulus.  Midgut volvulus 
should not be confused with cecal or sigmoid volvulus.  
Cecal and sigmoid volvulus generally occur in adults.  
Sigmoid volvulus involves the large bowel and can often 
be decompressed by barium enema or other 
non-surgical procedures.

VIew midgut volvulus.

     In midgut volvulus, the majority of the small bowel is 
involved in the stragulation.  Substantial small bowel 
necrosis occurs without prompt surgical intervention.

View cecal volvulus.

     In malrotation, the cecum may be prone to twisting 
or kinking if it is excessively mobile.  Cecal volvulus can 
occur in the absence of malrotation.  This most often 
presents in adults rather than children.

View sigmoid volvulus.

     Sigmoid volvulus is the most common site of colonic 
volvulus.  It occurs most often in the elderly.  It is 
associated with elongation of the descending colon 
making the sigmoid region hypermobile and prone to 
twisting.


     Midgut volvulus is a surgical emergency at risk of 
bowel infarction.  Some neonatal examples of volvulus 
are shown below.

View neonatal volvulus case. 

     This radiograph of a 5-day old infant with vomiting 
shows a gasless abdomen except for the small air 
bubble in the stomach.  Such a radiograph should be 
considered highly suspicious for any type of upper GI 
obstruction.  Further studies on this infant showed a 
midgut volvulus and malrotation.

View second neonatal case.

     This radiograph of a 9-day old infant with vomiting 
looks relatively normal.  It has a normal gas distribution 
with no air fluid levels or excessively dilated loops.  
Although this radiograph looks much more normal than 
the first neonatal radiograph, further studies on this
infant also showed a midgut volvulus and malrotation.  
Thus, it is not possible to rule out a volvulus due to 
malrotation solely on plain films in some instances.  
Clinical suspicion should lead one to pursue more 
definitive radiographic studies.  While sigmoid 
volvulus usually shows severely dilated loops of bowel 
and large air fluid levels on plain film radiographs, a 
midgut volvulus may show non-specific findings on plain 
films without the characteristic signs of an obvious 
bowel obstruction.

View BE of second neonatal case.

     This is a barium enema of the infant above 
which shows the ascending colon and cecum in the 
wrong place.  The cecum should normally be located in 
the right lower quadrant, but in this BE, most of the 
proximal large bowel is in the left upper quadrant.  The 
cecum is in the central abdomen.
     In a patient who has a malrotation but is not 
experiencing strangulation, malrotation is usually 
identified on an upper GI series or barium enema.  The 
UGI series can more definitively determine the 
presence of malrotation by identifying the position of the 
ligament of Treitz.  The BE can usually determine the 
presence of malrotation by noting the malposition of the 
cecum.  It should normally be located in the right lower 
quadrant.  If the cecum is located elsewhere, then 
malrotation is likely.  However, both of these studies 
can be deceiving at times.  The ligament of Treitz may 
be close to the normal location in a malrotation and the 
cecum may occasionally be in the RLQ in a malrotation.
     The classic presentation of malrotation is usually 
described as a volvulus, heralded by bilious vomiting in 
the first days of life.  Less than half of the cases 
actually present in the neonatal period.  Catastrophic 
midgut volvulus can present at any age.  Lesser 
degrees of reversible ischemia (sometimes called 
intermittent volvulus), can produce intermittent pain, 
non-bilious vomiting, gastroesophageal reflux, 
malabsorption and failure to thrive.  Patients with 
malrotation may be entirely asymptomatic with 
catastrophic volvulus occurring at any age.  Neither the 
age of the patient, nor the chronicity of symptoms are 
predictive.  All are at risk for severe complications (even 
adults).  The mortality of midgut volvulus in several 
series is 40 to 60%.  As some of these series date prior 
to modern intensive care techniques, the current 
mortality is probably lower, but the survivors may lose 
so much bowel that they are totally dependent on 
parenteral nutrition.  Due to this significant mortality and 
morbidity, even incidentally discovered malrotation 
should be surgically corrected.
     Intestinal obstruction is an uncommon cause of 
vomiting in the pediatric age group.  Most pediatric 
vomiting is caused by infectious agents, including viral 
gastroenteritis,  but also associated with generalized 
non-intestinal infections such as URI, otitis media and 
pneumonia.  Because of the relative preponderance of 
benign causes of vomiting, the serious causes must 
always be kept in mind and excluded or at least 
anticipated in discharge instructions.
     Vomiting in the neonatal period brings to mind 
sepsis, congenital anomalies or meconium ileus.  In the 
first few months of life, pyloric stenosis, hernias and 
intussusception are important causes of obstruction.  
As the infant becomes mobile, foreign bodies and 
poisoning must be considered.  Abdominal trauma, both 
intentional and accidental can produce vomiting.
     In addition to the above, remember A-A-I-I-M-M 
(AIM x2).  The diagnosis of appendicitis is sometimes 
obscure in the young patient.  There are no reliable 
tests to adequately exclude early appendicitis; 
therefore, anticipation of the need for early 
reexamination or observation in the emergency 
department should be considered in any child with 
abdominal pain and vomiting.

References
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the Intestines in Children:  The Effect of Age on 
Presentation and Therapy.  Journal of Pediatric Surgery 
1989;24:777-780.
     Andrassy RJ, Mahour GH.  Malrotation of the Midgut 
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Surgery 1981;116:158-160.
     Wang C, Welch CE.  Anomalies of Intestinal 
Rotation in Adolescents and Adults.  Surgery 
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     Ellenbourg DJ, Delcastillo J.  Duodenal Obstruction 
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