disease is a chronic, relapsing inflammatory disorder of human that can affect
any part of the gastrointestinal tract from Mouth to Anus. Specific symptoms include abdominal
pain, diarrhoea, fever, and weight loss. Other extra intestinal complications
may include anaemia, skin rashes, arthritis, inflammation of the eye, and
disease along with Ulcerative colitis(UC), form two major types of Inflammatory
bowel diseases (IBD). They are important because they result in long-term morbidity with
chronic inflammation, reduces quality of life and place significant demands on
Although progress has been made in understanding these diseases, their
specific aetiology remains obscure.(Molodecky et al., 2012).
Their incidence is increasing worldwide in a continuous manner, and the
diseases remain incurable. Research studies continue to show a rise in the
number of people living with inflammatory bowel disease (IBD), reflecting a
need for more research to find a cure.
Different between Crohn’s disease and
they share many similarities in the clinical features, the immune response in
CD differ from that observed in Ulcerative colitis. The inflammatory lesions in
Uncerative colitis are limited to colon
while in Crohn’s disease these can occur anywhere in the gastrointestinal tract
from mouth to anus, although most common sites of inflammation is observed in
terminal ileum (Baumgart & Carding,
clinical manifestations of crohns disease include discontinuous patchy
inflammations in different parts of the GI tract and the development of
complications such as stenosis, strictures, abscesses, and fistulae (Stange et al., 2006).
There are no specific clinical or
laboratory features that may help establish a diagnosis. Thus, diagnosis of UC
and CD relies greatly on pathologic interpretation of biopsy and resection
specimens (Geboes, 2001; Le Berre et al., 1995). Since both UC and CD have
a variety of characteristic, but non-pathognomonic features, it is important to
evaluate pathologic material in conjunction with clinical, laboratory,
radiologic and endoscopic features(Le Berre et al., 1995). Important clinical features of complicated UC in biopsy
specimens include diffuse continuous mucosal inflammation involving colorectum
without skip lesions, lack of submucosal involvement, lack of granulomas, absence
of deep fissuring ulceration, and lack of terminal ileum involvement (except
Typical letions of CD include transmural
inflammation (inflammation in all layers from mucosa to serosa), deep mucosal ulcers, increased goblet
cells, abscesses, fissures and granuloma formation; (Baumgart
& Sandborn), segmental involvement, less severe
disease in the distal colon compared to the proximal colon, rectal sparing,
patchiness of inflammation, terminal ileum involvement, upper GI involvement,
and a less prominent degree of mucosal architectural changes compared to UC.
Inflammation in UC typically involves the colon in a
continuous distribution, whereas CD usually involves the ileum and other
regions of the alimentary tract in a patchy, segmented manner (Podolsky 2002).
In UC, there is no
inflammation beyond the submucosal level and inflammatory cells such as
neutrophils are present in the lamina propria, with forming crypt abscesses and
associated depletion of goblet cells (and mucins) from the epithelium is
evident (Vatn, 2009).
some cases, a definite diagnosis of UC or CD cannot be made due to overlapping
features (“Indeterminate colitis”).
Epidemiology of Crohn’s Disease:
Disease incidence and prevalence:
IBD is thought to be associated with industrialization of nations, with
the highest incidence rates and prevalence of IBD in North America(Canada)(Bernstein, Blanchard, Rawsthorne, &
Wajda, 1999), Europe (Vind et al., 2006) and United kingdom.(Rubin, Hungin, Kelly, & Ling, 2000). The incidence of IBD rising in developing nations as they have become industrialized(Benchimol et
al., 2014; Desai & Gupte, 2005; Ng et al., 2013; Sood, Midha, Sood, Bhatia,
& Avasthi, 2003; Yang et al., 2014; Zheng et al., 2005). Industrialization seems to be an
environmental precondition for the increasing incidence, containing the most
important environmental components behind the initiation of the history of crohn’s
Several studies have reported
that the incidence of IBD has increased distinctly over the latter part of the
20th century, (Loftus, 2004;
LOGAN, 1998)while other studies have suggested a plateau
or even decline in incidence in certain geographic regions. (Loftus, 2004; LOGAN, 1998)
Although there are few epidemiologic data from developing countries, the
incidence and prevalence of IBD are increasing with time and in different
regions around the world, indicating its emergence as a global disease.(Molodecky et al., 2012).
Incidence is the frequency of new cases over a certain time interval and
is expressed as an incidence rate (the convention in the IBD literature is
cases per 100,000 person-years).
In a recent study, it has been found that the highest annual incidence
of UC was 24.3 per 100,000 person-years in Europe, 6.3 per 100,000 person-years
in Asia and the Middle East, and 19.2 per 100,000 person-years in North
The highest annual incidence of CD was 12.7 per 100,000
person-years in Europe, 5.0 per 100,000 person-years in Asia and the Middle
East, and 20.2 per 100,000 person-years in North America.
The highest reported prevalence for IBD was found in Europe where
prevalence of UC was 505 per 100,000 persons and that of CD was 322 per 100,000
persons whereas In North America the prevalence slightly lower than that (249
per 100,000 persons in UC and 319 per 100,000 persons in CD). In time-trend
analyses, 75% of CD studies and 60% of UC studies had an increasing incidence
of statistical significance (P