The most common complication of small bowel Crohn's disease is bowel
obstruction due to swelling. However, in a patient with small bowel
Crohn's, the wall becomes swollen due to chronic inflammation. Not only does it
swell outward, it swells inward too.
Other Types of
Blockages
Strictures
The chronic intestinal inflammation that characterises Crohn's disease
may also lead to the development of scar tissue in the intestinal tract.
As the cycle of inflammation and scarring continue, a segment of the
tract may be become narrowed in what is known as a stricture (sometimes called
stenosis). If a stricture narrows far enough, it may eventually obstruct
the intestinal tract.
Alternately, if a person with an intestinal stricture eats something
that is difficult to digest—for instance, raw vegetables, corn, popcorn, or
nuts—the food itself may lead to a bowel obstruction. Acute inflammation on top
of a stricture may cause the intestine to become blocked as well.
Because Crohn's disease affects the entire thickness of the bowel wall,
strictures are much more common than they are in ulcerative colitis, which
typically affects only the inner lining. With strictures, bowel obstructions
may be either acute (temporary) or chronic (permanent).
Adhesions
Adhesions are bands of scar tissue that develop normally after a patient
has surgery on the gastrointestinal (GI) tract.
Adhesions will run from the point of the surgery to other parts of the intestine,
other organs, or to the lining of the abdominal cavity (also known as the
peritoneum).
For most people, adhesions are painless and don't cause any problems at
all. However, for some patients, the adhesion may cause the intestine to become
"fixed." If a fixed intestine becomes twisted, it will cause an
obstruction.
Most bowel obstructions caused by
adhesions will get better without surgery, although, rarely, surgery will be
required to cut the adhesions and untwist the bowel. New adhesions will form
but will likely not cause problems.
Symptoms
The symptoms of a chronic blockage will be a "crampy"
abdominal pain, bloating, and nausea, which occur shortly after a meal. The
elapsed time between the meal and the symptoms will determine the site of the
blockage.
If it’ is less than one hour, the small intestine is usually the
culprit. Longer than one an hour suggests the blockage is in the colon. If the
symptoms happen all or most of the time after eating, it’ is likely the patient
is dealing with strictures as well as swelling.
In addition to the other symptoms,
vomiting, increased diarrhoea, or alternately, constipation, may sometimes
occur as well.
Treatments
A person with acute small bowel obstruction will usually get better
within 48 hours of beginning a clear fluid diet or taking prednisolone (a
powerful anti-inflammatory). In more serious cases, steroids and a sterilized
liquid (enteral) diet will usually help to reduce the swelling.
However, when the blockage is predominantly due to strictures, drugs,
are usually of limited effectiveness. In those more serious cases, the first
option for many patients is an endoscopy. In an endoscopy, a doctor passes an
inflatable balloon through an endoscope, thus dilating the area of scarring.
Success rates are as high as 75 percent with the endoscopy procedure. An endoscopy may
relieve symptoms for weeks, months, or even years for some people. However,
if the area isn't accessible with an endoscope, surgery will be necessary.
Surgery
The two types of surgery performed on patients with small bowel Crohn's
are resection, which involves removing the scarred area of the intestine, and
strictureplasty, which is like plastic surgery on the intestine.
The two types of Crohn's patients who are candidates for strictureplasty
include those who have had a previous resection, or for those for whom the disease
is very severe. Many of those who receive a strictureplasty are able to stop
taking medications that help heal the disease and maintain the remission of their
Crohn's.
Strictures that are opened with strictureplasty usually remain open as
well, and patients will generally only require surgery again if new strictures
form elsewhere in the small intestine or bowel. In addition, most people will
begin to eat normally (prior to their blockage) and even gain weight after the
operation.