So now, let's begin with a case.
A 35-year-old woman presents
complaining of 5 days of diarrhea.
She has had 5 bowel movements a day since
returning from a vacation in Mexico.
She has mild abdominal cramping but no
fever, blood in the stool or vomiting.
She has not taken any recent
antibiotics and takes no medications.
On exam, she is afebrile, heart rate
of 100, her blood pressure is 112/65
and her abdomen is soft and non-tender.
So we are asked, what is the
most appropriate management?
Let's look at some key clues in this case.
She has acute diarrhea, it's 5 days with a
recent travel history which may be a clue.
Her review of systems
is fairly unremarkable
and her heart rate being a little high at
100 may show that she has mild hypovolemia.
So before we answer this question, let's talk about your
general approach to the patient presenting with diarrhea.
When I see a patient with diarrhea, I always want to
ask how long the symptoms have been occurring for.
Another thing that is important to ask
is how often the stools are happening
and what are the
characteristics of that stool.
I also wanna ask about
any associated symptoms.
So, is there fever present?
Does the patient have abdominal pain or have
they lost weight due to their diarrhea?
The next thing I can ask is to probe a little bit
to see if the patient has any signs of hypovolemia.
So patients may describe a decline in their
urine output or dizziness with standing
which may be a sign that they
have orthostatic hypotension.
And lastly but probably the most important is
to ask about the patient's recent exposures.
So you wanna ask about
what they ate recently.
Have there been any unusual foods or
undercooked foods that they have eaten?
What do they do for work?
Where have they traveled recently, whether
inside or outside of their home country?
Do they have any pets or animal exposures that
might suggest different types of diarrhea?
And what do they do for their hobbies?
And lastly, you always
wanna ask where they live.
These can all help you to
determine the most epidemiological,
common illnesses that
may contribute to their diarrhea.
The next thing you'll always want to ask
about are alarm features in acute diarrhea.
So, you want to rule out any
severe abdominal pain, fever,
the presence of bloody stool,
recent hospitalizations or antibiotic use,
and this specifically places patients at risk
for developing an infection
called Clostridium difficile.
and if your patient belongs
to any special populations.
So are they elderly,
immunocompromised for some reason?
Do they have a known history of inflammatory
bowel disease, or are they pregnant?
These alarm features are
important to ask about because
if you can make sure that none
of these features are present,
then you do not need to do lab
studies for acute diarrhea.
So let's get to the
causes of acute diarrhea.
In developed countries, the most common causes are
viral gastroenteritis or food-borne illnesses.
There are many different organisms
that can cause acute diarrhea
including viral organisms such
as norovirus and rotavirus.
Many different bacteria can cause
limited episodes of acute diarrhea
including Salmonella and Shigella
and the others listed here.
and you may also have protozoal infections like
Cryptosporidia and Giardia that can lead to acute diarrhea.
Over here on the right, you can see
a limited list of the organisms
that are associated with
bloody or invasive diarrhea.
This is a list that you
should commit to memory.
So, most episodes of acute diarrhea are self
limited and thus they do not require lab testing.
For these patients, you can treat them with
supportive care and giving oral rehydration therapies.
However, if your patient has one or more
of those alarm features that we reviewed,
you should consider giving empiric antibiotics
if you suspect a bacterial infection.
So, some of the signs you may watch for are:
severe disease with a fever, more than 6
stools a day or signs of volume depletion,
or if the patient has bloody
stools in the presence of fever
or if they are a typically
So if their age is greater than 70
or if they are immunocompromised.
So now that we've reviewed that,
let's return to our case.
We have a 35-year-old woman
who's presenting with acute diarrhea,
with a recent travel history to Mexico.
Her review of systems is
unremarkable and now we know that
she has no alarm symptoms
for invasive diarrhea.
In addition on her physical exam,
she has signs of mild hypovolemia.
So, we can now put these altogether
and make the diagnosis of
acute diarrhea likely from a food-borne
illness due to her recent travel.
Now, what is the most
Because she has no alarm features present,
we can manage her with supportive care
and oral rehydration therapy.