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 ulcerative colitis.
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.
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 bowel disease.
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 ulcerative colitis.
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 perianal disease,
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.