Crohn's Disease: Pathophysiology, Symptoms, Risk factors, Diagnosis and Treatments, Animation.
Crohn disease: pathophysiology, symptoms, causes, risk factors, complications, diagnosis and treatments. This video is available for instant download licensing …
Crohn’s disease is one of the 2 major forms
of inflammatory bowel disease.
Inflammation caused by Crohn’s disease may
affect any parts of the gastrointestinal tract,
but it most commonly involves the end of the
small bowel, the ileum, and the beginning
of the colon.
The inflammation is not continuous, inflamed
segments are usually interrupted by normal
Most people experience recurrent flares, when
the disease is active, followed by symptom-free
periods of remission.
Symptoms may differ depending on the parts
of the digestive tract that are affected.
Most common signs include diarrhea, abdominal
pain and tenderness, loss of appetite, weight
loss, fatigue and fever.
Blood in stools occurs when the colon is involved;
nausea and vomiting are usually the signs
that the stomach or the first part of the
small intestine is affected.
About one third of patients present with perianal
disease, including abscess, fistulas and ulcers.
The disease also often manifests outside the
intestine, especially in the joints, skin,
Inflammation in Crohn’s disease extends
to the entire thickness of the intestinal
Deep lesions in the mucosa often alternate
with areas of mucosal swelling, creating a
characteristic cobblestoned appearance.
Extensive inflammation may cause thickening
of the bowel wall and hypertrophy of the mesenteric
fat that wraps around the intestine.
Intestinal wall thickening, together with
scar formation, may block the flow of digestive
content, leading to bowel obstruction.
Ulcers can extend through the bowel wall and
form tunnels, called fistulas, which may connect
to other loops of the intestine, to abdominal
organs, muscles and even skin.
A fistula may become infected and form abscesses,
which can be life-threatening if not treated.
In the long-term, Crohn’s disease may increase
risks for colon cancers.
The disease has a major peak of onset between
the age of 20 and 30, and a smaller peak later
White individuals, people with family history,
and smokers are at higher risks.
The exact mechanism of Crohn’s disease is
not fully understood, but it likely involves
both genetic and environmental factors.
Multiple genes are identified, most of which
act in the immune system, or in maintaining
the gastrointestinal epithelial barrier.
This barrier separates the gut content from
the underlying immune system, preventing the
body from reacting to dietary antigens and
resident bacteria of the gut.
A crack in the barrier may increase the chance
that the immune system overreacts to non-pathogenic
antigens from the gut content.
Involvement of environmental factors is evidenced
by higher disease incidence in developed countries,
especially urban areas.
Diagnosis is made based on a combination of
tests and imaging procedures.
Treatments start with dietary management to
maintain good nutrition but avoid foods that
may exacerbate symptoms.
Some patients may benefit from nutrition therapy,
a special diet given via a feeding tube or
injected into a vein.
The therapy provides nutrition while allowing
the bowel to rest, reducing inflammation.
A number of medications can be prescribed
depending on disease severity and the patient’s
response to different drugs.
These may include: antidiarrheals, anti-inflammatories,
antibiotics, corticosteroids, immunomodulators
Abscesses and fistulas are drained and treated
Nearly half of patients require at least one
surgery to manage recurrent intestinal obstructions
or complicated fistulas or abscesses.
Surgical removal of the diseased parts of
the bowel may improve symptoms temporarily,
but is not a cure, because the disease is
likely to recur, usually near the reconnected