In this lecture, we’re going to review the
basics of inflammatory bowel disease.
Whole books have been written about this,
but we’re going to try to
cover the features that are
most likely to show up on
a multiple choice exam.
So inflammatory bowel disease, a
few things we need to understand.
The incidence is increasing
in the United States.
This is probably because fewer and
fewer children are exposed to things
that are training their immune
system in that first year of life
not to attack itself.
25% of patients are going to present
in childhood or adolescence.
So this is somewhat an adult disease,
but also it’s a pediatric disease
and there some differences.
Environmental triggers in
genetically predisposed individuals
are what caused this disease.
It’s a combination of
environment and genetics.
Clearly, poor health, restricted growth,
and adverse psychological well-being are
consequence of inflammatory bowel disease.
This is a disease where we have to
deal not only with the intestine,
but the person as a whole.
So what part of the
bowel are affected?
Well, it’s different depending on which type
of inflammatory bowel disease you have,
be it Crohn’s or
Crohn’s disease can affect any part
of the GI tract from mouth to anus.
Ulcerative colitis only affects the colon.
So the epidemiology of IBD is
that there is a bimodal peak
of when this disease
is first recognized.
With an uptake during the late childhood
period and then into young adulthood
and then fewer diagnoses
until the 40s, 50s and 60s.
While it is rare, I have
even seen children diagnosed
with inflammatory bowel disease
as early as year of age.
But these are the peak ranges
when this diagnosis is made
and because I’m speaking about pediatrics,
I’m going to talk about the younger group.
Remember that the mean age of diagnosis
in the United States is in children,
so it’s appropriate for us to
be discussing this problem.
The average age being 12-1/2.
And 20% of cases in children are
diagnosed before 10 years of age.
So we have to think about
this even in the young kids.
So who’s affected more often?
Well, in ulcerative colitis, it’s more
often affected men than it affects women
whereas in Crohn’s disease,
these groups are roughly equal.
Inflammatory bowel disease is more
prevalent in the first world.
Developing countries have a
lower rate of this problem.
This probably relates to early
childhood exposure to infections
and especially to worm infections
which seem to be protective
for developing the illness.
So risk factors for inflammatory bowel
disease include a positive family history,
which is seen in roughly
one in four patients.
Patients with Jewish ancestry
are at increased risk
for developing inflammatory
Patients who are exposed to smoke
have an increased risk of
development of Crohn’s disease.
But ironically, smoke exposure decreases
risk of developing ulcerative colitis.
I would not propose that you
encourage patients to smoke
because of a decreased risk of ulcerative
colitis, but that is something we’ve seen.
Interestingly, appendectomy may be protective
for the development of Crohn’s disease.
Nobody has a clue why.
So inflammatory bowel
disease is going to present
a little bit differently
depending on whether the disease
is Crohn’s disease or
However, there are some
consistencies between the two.
All of these patients will
present with abdominal pain,
weight loss, and intermittent fevers.
Patients with Crohn’s
disease will have diffuse
or right lower quadrant
crampy abdominal pain.
They may have non-bloody, melanotic
or frank blood in their diarrhea.
They will see more
so you’ll see tags, fissures,
other problems, fistulas
around the anal area.
So a perianal exam is
important on these patients.
And they also can develop recurrent
aphthous ulcers in the mouth.
Patients with ulcerative colitis
will develop diffuse abdominal pain.
They may develop bloody diarrhea
and they may also develop fecal
urgency and increased frequency.