Let's move to our next case.
A 33 year old man is seen in clinic for a 10-week history
of diarrhea and worsening abdominal crampy pain.
He has 6 to 8 bowel movements a
day, including a few at night.
His stools are loose with streaks of blood and
he has poor appetite and nausea but no fever.
He does not take
On exam, he is afebrile with a heart
rate of 100 and blood pressure of 95/50.
His abdomen is soft with moderate
diffuse tenderness in the lower quadrants
with no rebound or guarding.
Colonoscopy shows patchy colitis with
deep ulcers in a cobblestoning appearance
and there is no involvement of the rectum.
So, what is the most likely diagnosis here?
Let's look at some clues in this case.
So he has chronic diarrhea.
The presence of blood in the stools indicates
that he may have an inflammatory diarrhea.
On his physical exam, he is
tachycardic and mildly hypotensive
which indicates probably,
signs of mild hypovolemia.
And there is some keywords on his colonoscopy
report such as cobblestoning and rectal sparing.
So, we put this altogether, he
has chronic, bloody diarrhea
which should automatically raise your
suspicion for an Inflammatory Bowel Disease.
In addition, his colonoscopy report with patchy
colitis and cobblestoning with rectal sparing
should prompt you to think
about Crohn's disease.
So, let's talk a bit more about IBD.
There are 2 types of IBD, they are
Crohn's disease and ulcerative colitis.
They have very common clinical features and
that they can both present with hematochezia,
abdominal pain and fever, weight loss,
a sense of fecal urgency or tenesmus.
They can both also present with
symptoms outside of the GI tract.
So things like jaundice, uveitis,
arthritis and lesions on the skin.
For the diagnosis, you first want to rule out any
infection that could be contributing to their symptoms.
So, you would check a stool culture, a
C. difficile toxin and a stool ova and parasites.
You may next also look for signs
of inflammation in the stool.
So, a C-reactive protein or CRP and
an elevated sedimentation rate or ESR
can be helpful to look
for systemic inflammation.
A fecal calprotectin can also be helpful because
this is an inflammatory marker inside the stool
that can help you track
progression of the disease.
Lastly, you may do a colonoscopy to look
for the specific features of each disease.
The treatment depends on the type.
So let's go into
specifically Crohn's disease.
Crohn's disease is a transmural inflammation
that can affect really any part of the GI tract.
So, the symptoms or clinical
features you may encounter
are diarrhea, abdominal pain, basically
any symptoms involving the intestine.
You may have rectal bleeding, in the
stomach, they may have vomiting,
and it can also affect the liver and
bile duct leading to inflammation.
Outside of the GI tract, patients may
have inflammation or uveitis of the eyes.
They may develop skin ulcers and sores,
One typical rash that we see
often is erythema nodosum.
They may also have systemic signs of fever,
weight loss and anorexia or decreased appetite.
They may also have ulcers in the mouth.
These patients tend to have frequent
flares and remissions of their disease.
And because of the transmural inflammation, so that's
inflammation extending through the wall of the bowel,
there are common complications such
as fistulae and bowel obstructions.
Treatment is done with
corticosteroids for flares
and for maintenance therapy, we give
immunomodulators such as methotrexate
or more advanced biologic agents that target
the anti-TNF pathway such as infliximab.
Most patients, because of their relapsing and
remitting disease will eventually require surgery.
Now let's talk about ulcerative colitis.
So, unlike Crohn's disease
which is a patchy inflammation
involving any part of
the GI tract shown here,
ulcerative colitis is a continuous inflammation that
involves the colon and the rectum as shown here.
It usually does not involve the small bowel
and it is associated with diagnoses like
primary sclerosing cholangitis, cholangiocarcinoma
and higher rates of colorectal cancer.
The treatment as with Crohn's is with
first, corticosteroids for flares.
For maintenance therapy, we also give
5-aminosalicylic agents like mesalamine.
and we also have immunomodulators
and biologics for severe disease.
So you might be thinking at this point that a Crohn's
disease and ulcerative colitis have a lot in common.
So how do we tell them apart clinically?
These are some clues that can
help you make the diagnosis.
So Crohn's disease, again involves inflammation of
the entire bowel wall, so transmural inflammation.
Also, patients tend to have skip lesions, so
patchy involvement and a cobblestoning appearance.
They often have spared areas on colonoscopy.
On the other hand, ulcerative colitis involves
inflammation limited to the mucosa and the submucosa only.
and inflammation tends to be continuous,
so there are no skip lesions.
The location also differs.
With Crohn's disease, this can
involve any part of the GI tract.
It typically, however, spares the rectum.
And the terminal ileum
is the most common site.
With ulcerative colitis, only the
rectum and the colon are involved.
The last thing to distinguish between
the two are the common complications.
So if you remember that Crohn's disease
involves transmural inflammation
then you'll remember that fistulae and
abscesses are more common with this disease.
With ulcerative colitis, associated complications
are a higher risk of colorectal cancer
and the association with the diagnosis
of primary sclerosing cholangitis.