In this lecture, we’ll be
speaking about gastroenteritis,
and vomiting and
diarrhea in children.
Let’s first talk about vomiting.
Vomiting is obviously a forceful,
coordinated expulsion of stomach contents.
If you see a patient
you need to take a very good
history and a complete history.
You need to do a
focused physical exam.
You need to do some lab work.
And you may need to do
some imaging studies.
Let’s talk about what exactly
we do under what circumstances.
So, in terms of the history,
it’s key to figure out if
the child is dehydrated.
In a child with vomiting,
dehydration can happen
And typically, in children,
they can look very, very well
and then suddenly
get much sicker.
So, a good history about
whether the child was drinking
and whether the child has good
urine output is important.
It’s important to assess what the color
of the vomit is, especially in babies.
Bloody emesis may be indicative
of something in the esophagus
like Mallory-Weiss tears, or problems
in the stomach like gastritis.
But in particular, in babies, green
emesis may indicate bilious emesis.
And while in adults, we think
of bilious emesis as just
the end result of a prolonged
period of vomiting.
In infants, this may be indicative
of a malrotation of the intestines,
which may be a
You should ask about associated symptoms.
It’s perhaps this vomiting that’s from
something other than the GI tract.
For example, if a patient has hydrocephalus
or increased intracranial pressure,
vomiting may occur, and it’s
the vomiting you’re noticing
and not the fact that the
child is having some
problems with the pressure
inside their head.
The renal tract also
can cause vomiting,
either through stones or
urinary tract infection.
It’s important to ask about
the duration of symptoms,
and we’ll discuss chronic versus
acute episodes of gastroenteritis.
But understanding how long
this has been going on for
may give you clues
as to the etiology.
Typically, viral illness is
reasonably short, only a few days.
Other illnesses can last
a much longer time.
Timing in relation to feeds
is important because it
may give you a clue as to
what organ is involved.
A few examples:
If a baby has a problem
with their esophagus,
they’ll often spit up
immediately after the feed.
If the problem is in the stomach,
there may be a slight delay.
If the problem is in the pancreas,
a patient may not feel pain for
up to an hour after eating.
Social history is always important
and may give you some clues as to what’s
actually going on with this patient.
I have, in the last months,
seen a patient who had vomiting
and it turned out the cause was in fact
child abuse and blunt head trauma.
So let’s shift the gear and look
towards physical exam findings,
and there are some key
physical exam findings
that are important in any
child with vomiting.
Signs of dehydration, as in addition to the
history, can be found on physical exam;
dry mucous membranes, a
delayed capillary refill,
things along that nature.
If a patient has peritonitis
or an acute abdomen,
you know this is going to
be a very different problem
than just acute viral illness.
A patient with an appendicitis
can have pain with palpation
or a rebound or guarding
over the abdomen.
And remember, diseases
like appendicitis can
be very tricky to pick
up in small children.
In fact, a sizable percentage are
missed until they perforate.
A complete physical exam
is important to understand
all the extra abdominal
etiologies of vomiting.
So, understanding, for example,
their pupillary reflex is important if
you’re worried about increased ICP.
So if you’re seeing a child who’s vomiting
and you’re curious what labs you might get,
let’s go through them
a little bit at a time.
the Chem-7 is generally a reasonable
lab to get in a child who’s vomiting
and you’re not sure
what’s going on.
A high BUN to creatinine ratio is going
to be indicative of dehydration.
If the patient has a very high
creatinine but not a very high BUN,
you might think about renal causes of
emesis as opposed to just dehydration.
Generally, in patients with significant
dehydration, there will be some acidosis.
Some practitioners like to use a cut-off
of say about 14 for the bicarb in a Chem-7
in terms of where you
would worry about a child
in terms of their ability
to continue hydration.
Others feel that it’s simply a
matter of giving the child a drink
and seeing how they do and using
their clinical appearance
to determine whether these
children need to be
hospitalized or whether
they can be sent home.
Excessive vomiting may cause an alkalosis.
The classic example would be an
infant with pyloric stenosis,
and we’ll talk about pyloric
stenosis in another talk.
But an infant with pyloric
stenosis will have
excessive vomiting and loss
of acid out of their vomit,
and that will present as an
alkalosis on the Chem-7.
A urinalysis is commonly performed
because infants, especially,
can’t tell you when they have
symptoms of urinary tract infections,
and urinary tract infections
are more common in infants.
A lumbar puncture is absolutely
indicated if meningitis is concerned.
remember the clinical context because we
wouldn’t want to do a lumbar puncture
in someone with acutely raised ICP
unless you knew exactly
what was going on.
LFTs and a lipase are useful.
I know on your slide it says amylase,
and that probably may be on a test,
but we’ve actually stopped getting amylase
as much as a test for pancreatitis.
It’s much more the lipase because
the amylase is nonspecific
and may be from the
Don’t always forget,
adolescents can get pregnant,
and a pregnancy test is almost always
indicated in an adolescent female
who presents with vomiting
of unclear etiology.
So let’s talk about imaging studies
you might get in a vomiting child.
Well, first, the abdominal X-ray.
Generally, we’ll get an upright
picture in an older child
because that will allow us to see things
like free air under the diaphragm.
And as you can see on the slide here,
you might see air fluid levels.
This patient with multiple air fluid
levels probably has a gastroenteritis.
You can see that fluid contents
will layer out with nice lines,
and that gives us a sense
that the issue here is that
the intraintestinal compartment is containing
liquid as opposed to solid material.
We will get an upper GI
in some circumstances
where we suspect
Remember that the regular upper GI does
follow through the ligament of Treitz.
That means that if you have that
bilious emesis in an infant
where you’re worried about malrotation, a
regular upper GI is all that you need.
An upper GI will also show you
something like pyloric stenosis.
A small bowel follow through
is really only used
where you’re concerned
about small bowel disease.
We don’t need to get that for a
patient with concern for malrotation.
We might get that test for someone, for
example, with inflammatory bowel disease
where you’re worried there might be
some small intestine abnormalities.
However, we’re really moving
more towards intestinal MRI
as opposed to small bowel follow
through for those patients.
Ultrasound is a mainstay for
many diseases in children.
We’ll use an ultrasound for things like
pyloric stenosis and intussusception.
And actually, some practitioners
are getting much better at it
and we can even evaluate for
things like malrotation.
The abdominal CAT scan
is a very useful test
for patients where we’re worried
about intraabdominal pathology.
But remember, there’s quite a bit
of risk for radiation in children.
Children, who are young,
have more mitosis
and are greater risk for
developing cancer down the line.
As a result, most centers are moving
gradually away from the abdominal CAT scan
and more towards ultrasound.
Abdominal MRI is an evolving tool,
and we’re getting better at using
it in certain circumstances.
Certainly, we use it for
inflammatory bowel disease
as a way of assessing the
small bowel in children.