In a day-to-day practice, general pediatricians are expected
to care for a wide variety of gastrointestinal disorders. Fortunately,
most of the gastrointestinal aliments in childhood are not serious
and self-limiting in nature and do not usually require a referral
to a sub-specialty such as pediatric gastroenterology with few exceptions.
Inflammatory bowel disease (IBD) is an exception; consultation with
a pediatric gastroenterologist is mandatory for adequate management. Crohn’s
disease (CD) and ulcerative colitis (UC) are the two most common
chronic IBDs. For decades, CD and UC were considered totally different
entities, since the clinical features, treatment options, and natural
history of these diseases appeared to be quite different. However,
recent developments and findings have made clinicians and scientists
begin to think of IBD as one entity, with a spectrum of findings.
Recent work has, for example, identified CD and UC occurring in
the same families, common susceptibility genes and pathways between
these two entities, and similar responses to emerging therapies
to both conditions. Classic CD is found at one end of the spectrum
and UC at the other, but many patients have features that overlap.
In this chapter, we will try to approach CD and UC as one entity
but differentiate CD from UC whenever necessary.
Although a diagnosis of IBD can be made at any age, about one
in every four new diagnoses of IBD is made before the age of 20
years. Population-based studies suggest that IBD is unevenly distributed
throughout the world, with the highest disease rates occurring in
Western or industrialized countries. Recent epidemiologic surveys
have also suggested that IBD incidence rates have changed over the
second half of the twentieth century, with a gradual increase in
CD, but reaching a plateau in UC incidence.1 Only a few
systematic, population-based studies have been done in North America
regarding the true incidence of childhood IBD to date, and estimate
the incidence is about 7–12 per 100,000 children. Although
the true impact of IBD in children is not entirely known, we estimate
that about 100,000 children are suffering from IBD in North America
at any given time.2 This makes IBD one of the common chronic
gastrointestinal disorders for which pediatricians and pediatric
gastroenterologists provide care.
There are differences in the descriptive epidemiology of IBD
when pediatric IBD is compared with adult-onset IBD. While CD and
UC occur with equal distribution in adults, the incidence of CD
is three times higher than UC in pediatric age groups.2 In
adult IBD, there is a nearly equal ratio of male to female disease,
with a slight female predominance. In contrast, prepubertal children
with CD exhibit a male preponderance of 1.5:1.3 Currently
there is no molecular explanation why children with IBD differ from
adults in regard to gender ratio.
The etiology of IBD is not completely understood at present,
although significant advances have been made over the last decade.
It is becoming increasingly more evident that certain ...