Crohn’s
Disease Diagnosis
Typically the diagnosis of Crohn’s disease is based on a
combination of laboratory tests, X-rays, and endoscopies. An
endoscope is an instrument used to visually examine a body cavity or
hollow organ like the colon, bladder, or stomach.
Laboratory Tests
Your physician will normally order a CBC (complete blood count)
test. If the result of the CBC reveals a high white blood
cell count this could be an indicator of
inflammation. If a low red blood cell count is
discovered this could mean intestinal bleeding. The CBC can
also screen for the presence of C-reactive protein which can indicate
intestinal inflammation. Patients suffering from chronic
diarrhea will
have low blood proteins and minerals.
Liver tests can also be performed to search for abnormalities in the
liver and bile ducts.
A stool sample may be requested to search for the presence of treatable
bacteria infections and rule out other causes of bloody diarrhea.
Endoscopic Exams
There are a bevy of endoscopic exams that a Crohn’s disease
patient may have to endure before being diagnosed with
Crohn’s disease.
These exams will aid your GI in ruling out other conditions that
resemble an IBD such as Irritable Bowel Syndrome (IBS), sometimes
humorously referred to as ‘spastic
colon’. IBS causes many of the same
symptoms (diarrhea, cramping, bloating) but are not caused by
inflammation as in Crohn’s disease or Ulcerative Colitis.
Sigmoidoscopy
Before your physician orders a colonoscopy they may perform a
sigmoidoscopy. Sigmoidoscopies can be performed by your
general physician in their office.
A sigmoidoscopy is an internal examination of the lower large intestine
called the sigmoid colon. A flexible fiber optic tube with a
camera at the end, called a sigmoidoscope, is inserted into the
rectum. The scope will exam the last 20
inches or so of your colon. During this time your
doctor may perform a biopsy (removal of a small piece of tissue) of the
bowel walls.
Reason to hate:
- What the doctor describes as ‘pressure’
from the scope is quiet uncomfortable.
- Most experience a discomforting urge to defecate.
- Sometimes there is a feeling of cramping or bloating from
the air inserted into the bowel during the exam.
On the plus side:
- You can’t feel the biopsy.
- Prep is fairly simple, involving a self administered enema
one hour before the test.
Colonoscopy
A colonoscopy is similar to a sigmoidoscopy except that it allows your
doctor to examine the entire length of the large intestine
(colon) and generally anesthesia is used. Using a fiber optic
camera at the end of a flexible
tube, a visual inspection is made to search for inflammation, growths,
and ulcers.
For the exam, the colon must be free of material which requires a
fairly extensive
bowel preparation. This
typically includes a
liquid diet lasting 1 to 3 days. In additional to the liquid
diet you will be asked to consume a special cleansing solution designed
to encourage emptying of the bowels. There are several
different varieties out there with the most common being Halflytely,
Golytely,
Nulytely, Colite, and Phospho Soda.
The quantity of fluid varies between brands but the general directions
are to drink an 8 ounce glass every 10 to 15
minutes. It can take 30 minutes to several hours to
‘kick in’. It’s a good idea to
stay near a toilet, since once that happens the bowel movements can
come fast and frequently.
Before beginning the procedure the patient is often given sedation
intravenously. The sedation, commonly referred to as twilight
anesthesia, minimizes the amount of discomfort felt during the
procedure. Many patients aren’t aware of the exam
and don’t remember anything. The exam itself last
30 to 60 minutes, the patient lies on their left side or back as the
doctor slowly advances the scope through the large intestine and
examines the lining.
After the procedure, expect the recovery from the sedation to last one
to two hours. Some people experience cramping and the feeling of having
to pass gas afterwards.
Reason to hate:
- Extensive bowel preparation ritual before
the exam is
arguably the worst part, especially the drinking of large volumes of
marginally potable fluids.
- Potentially uncomfortable bout of flatulence afterwards due
to the introduction of air during the exam.
- Because of the sedation you can’t drive yourself
home from the exam.
On the plus side:
- Since you’ll be under sedation for the exam you
won’t feel anything or at least you won't care.
- They may print off a few snapshots of the inside of your
colon that later can be added to the family album.
- Very low risk of complications, around 0.2%.
- All polyps found are removed for no extra charge.
Capsule Endoscopy
A relatively new procedure, capsule endoscopy involves the patient
swallowing a small vitamin sized camera. The camera capsule
takes images of the small intestine reaching the areas that older, more
invasive
tests can not. The capsule is taken with a drink of water and
is ‘recovered’ approximately eight hours
later. The capsule endoscopy is not a replacement
for traditional methods of endoscopy but is still an additional
diagnostic tool for diagnosing GI disorders.
Reason to hate:
- Can’t be used solely to diagnose
Crohn’s disease.
- Generally very safe but there is a small chance that if
there is
a partial blockage of the bowel the capsule could get lodged in the
intestines and require surgery.
On the plus side:
- Requires no extensive or uncomfortable preparation.
- You get to wear a fancy high tech computer attached to your
belt, that the camera will transmit pictures to during its journey
through you.
X-Rays
Barium Enema
A barium enema or lower GI series allows your doctor to evaluate your
colon by X-ray. Before the test begins a contrast dye called
barium is deposited into your colon via
enema. Barium is a white chalky substance which
fills and coats the lining of
the bowel and enhances the pictures taken by the x-ray.
When air is also inserted along with the barium it is called an air
contrast barium enema. This is a method for finding polyps
and small cancers.
Preparation may include a clear liquid diet the day before the test, as
well as enemas.
Reason to hate:
- During the test the feeling of
‘fullness’ or ‘discomfort’ can
be unpleasant.
- Bowel movements after tests are white and chalky.
On the plus side:
Upper GI Series
The upper GI (gastrointestinal) series uses an x-ray to exam the upper
gastrointestinal tract consisting of the esophagus, stomach and the
first part of the small intestines called the duodenum.
Sometimes it can be used to exam the rest of the small intestines as
well.
Before the x-ray the patient drinks a milkshake-like liquid containing
barium. The barium provides a contrast by coating the
esophagus, stomach and duodenum. After swallowing the barium
the radiologist will take a series of x-rays as the barium moves
through your
system. The procedure will take between one and two hours.
Reason to hate:
- Some people may feel nauseous after drinking the barium.
- Possible to have either constipation or diarrhea after the
exam.
On the plus side:
- Preparation is simple, no food or drink after midnight the
night before.
- Barium ‘milkshake’ might have a fruit
flavor added.
- No invasive probes used.
CAT or CT Scan
A CAT (Computerized Axial Tomography) or CT scan is an x-ray that
creates images of the pelvis and abdomen. This procedure
aides in finding abscesses or fistulas by examining the entire bowel
and tissues surrounding the GI tract.
The patient lies down on a movable table allowing a large doughnut
shaped device to take x-ray images of the abdomen at different
angles. The images are then processed by computer and
produces cross sections or ‘slices’ of the
patient’s abdomen.
Reason to hate:
- Probably not the only test required to diagnose an IBD.
- Contrast may be used, taken either by mouth or injected
intravenously.
On the plus side:
- No barium to drink or insert anywhere else.
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