This is a 16-month old male who presents to the 
emergency department with a two day history of 
fussiness, abdominal pain, and vomiting.  His mother 
attempted to cure his condition by administering herbal 
teas and herbal enemas.  He became poorly responsive 
which promoted his mother to bring him to the E.D.  He 
has felt warm, but his temperature was not measured at 
home.
     Exam:  T 37.4 (rectal), P195, R40, BP 99/54, 
Oxygen saturation 98% in room air.  He is drowsy but 
arousable.  Eyes somewhat sunken.  TM's normal.  
Oral mucosa sticky.  Lips dry.  Neck supple.  Heart 
regular, tachycardic, without murmurs.  Lungs clear.  
Abdomen shows moderate distention with intermittent 
hypoactive bowel sounds.  There is diffuse tenderness.  
No masses are appreciated.  No hernias.  Testes are 
normal.
     IV fluid hydration is started.  Blood studies are 
drawn.  A nasogastric tube is inserted.  Greenish fluid 
returns.  Abdominal radiographs are obtained.

View abdominal radiographs.
[Supine view]



[Decubitus view]

     The decubitus view is a left lateral decubitus film 
(left side down).  The flat view is taken in the supine 
position.  There is a nasogastric tube with its tip in the 
stomach.  There is no evidence of free air.
     Review Case 18 in Volume 3 (Test Your Skill In 
Distinguishing Bowel Obstruction From Ileus) to review 
the radiographic findings consistent with a bowel 
obstruction.  Assessing these criteria in this set of 
radiographs follows:
     a) Gas distribution:  Gas is distributed throughout 
the abdomen except for the right lower quadrant on the 
supine view.
     b) Bowel distention:  This is best assessed by the 
smoothness of the bowel walls rather than measuring 
the diameter of the bowel lumen.  In a bowel 
obstruction, the bowel acquires a smooth appearance 
resembling large hoses or sausages.  As the bowel 
distends, it loses its normal plicated/haustrated 
appearance and the bowel walls become smooth.  In 
this case, the bowel is distended (smooth and 
sausage-like).
     c) Air/Fluid levels:  There are several large air fluid 
levels seen on the lateral decubitus view.  While small 
air/fluid levels are most often indicative of an ileus, large 
air fluid levels with J-shaped (candy cane or hairpin 
turns) loops are more suggestive of a bowel 
obstruction.
     d) Orderliness:  This is best appreciated on the flat 
(supine) view.  In this case, the gas pattern is orderly 
rather than disorderly.  In other words, it resembles a 
bag of sausages more so than a bag of popcorn.  The 
orderly (bag of sausages) appearance is more 
indicative of a bowel obstruction.

     Both the flat and left lateral decubitus films show 
considerable bowel dilatation.  There are large air/fluid 
levels on the decubitus view.  This is consistent with a 
distal mechanical bowel obstruction.  In addition to the 
findings of a bowel obstruction, there is granular 
radioopaque material in the bowel (mostly colon).
     Upon obtaining further history inquiring about his 
diet, he has a history of eating sand, dirt, and glass.  It 
is likely that the granular material in the bowel is 
probably a mixture of sand and other debris.  How does 
this affect our treatment approach ?

     While barium studies may be useful to further image 
his bowel, at this point, he is felt to have an acute bowel 
obstruction.  Clinically, his degree of abdominal 
distention and tenderness is felt to necessitate a 
laparotomy.  What about the possibility of the sand and 
other debris obstructing the bowel ?
     At this point, the differential should include, 
intussusception, appendicitis, and midgut volvulus.  In 
general, causes of bowel obstruction include conditions 
that start with AIM:
     Adhesions
     Appendicitis
     Intussusception
     Inguinal hernia (incarcerated)
     Malrotation
     Meckel's
     Masses
     Miscellaneous

     At laparotomy, he is found to have a midgut volvulus 
with necrotic bowel caused by a tight band around a 
Meckel's diverticulum.  The necrotic bowel is resected 
and viable bowel is reanastomosed.  There is no 
evidence of bowel perforation.  The radioopaque sand 
and other debris seen on the abdominal radiographs 
were "red herrings".  A further imaging work-up would 
have only delayed surgical intervention.

Discussion
     Two percent of the population are born with a 
Meckel's diverticulum (one in fifty !!).  It is located 50 to 
75 cm proximal to the terminal ileum.  Meckel's 
diverticulum is most often asymptomatic as only 2% of 
those with Meckel's diverticulum manifest clinical 
problems.

The Meckel's rule of 2's:
     a) 2% of the population are born with a Meckel's.
     b) Only 2% of those with a Meckel's manifest clinical 
problems.
     c) Usually located 2 feet proximal to the terminal 
ileum and the diverticulum is usually 2 inches long.
     d) Symptoms commonly manifest at age 2 years.

     The most common presentation of a Meckel's 
diverticulum is painless intestinal bleeding.  The 
Meckel's diverticulum contains ectopic acid-secreting 
gastric mucosa.  The epithelium in the Meckel's 
diverticulum may ulcerate and bleed.  Slow bleeding 
may present with signs of iron deficiency anemia and 
occult stool blood loss or melena.  More rapid bleeding 
may present with hematochezia.  An ulcerating 
Meckel's may also perforate leading to peritonitis and 
an acute abdomen.
     Less commonly, a Meckel's diverticulum may 
present as a bowel obstruction or with abdominal pain.
The base of the Meckel's diverticulum may form a 
leading edge for an ileal intussusception.  If the 
Meckel's diverticulum is still attached to the anterior 
abdominal wall, this may predispose one to a volvulus.  
Both of these presentations will present with signs and 
symptoms of a bowel obstruction.
     A Meckel's diverticulum may become inflamed.  This 
results in abdominal pain with a clinical picture similar to 
that of appendicitis (see Case 9 of Volume 4, 
Periumbilical Abdominal Pain).  If a Meckel's 
diverticulitis perforates, it will lead to peritonitis.  One 
mechanism of Meckel's diverticulitis is a volvulus of the 
diverticulum itself leading to ischemic necrosis.
     Meckel's diverticulum can be diagnosed on 
scintigraphy.  The so-called Meckel's scan is based on 
an isotope labeled compound that localizes in gastric 
mucosa.  This isotope normally accumulates in the 
stomach and bladder.  Additionally, upper GI peristalsis 
carries the isotope into the duodenum and proximal 
jejunum.  A positive study will demonstrate a hot spot in 
the lower abdomen, usually on the right.  The 
pre-treatment administration of pentagastrin and 
cimetadine may improve the accuracy of the scan.
     Barium studies will sometimes identify a Meckel's 
diverticulum.  However, upper GI series and barium 
enemas cannot be used to reliably rule out a Meckel's 
diverticulum.
     Meckel's diverticulum is often diagnosed at 
laparotomy when surgical intervention is indicated, such 
as in a bowel obstruction refractory to conservative 
measures, a refractory intussusception, a suspected 
volvulus, a rule-out appendicitis or an acute abdomen.

Reference
     Goglia RP.  Meckel's Diverticulum.  In:  Ashcraft 
KW, Holder TM (eds).  Pediatric Surgery, second 
edition.  W.B. Saunders, Philadelphia, 1993, pp. 
435-439.