disease is one of a group of disorders called inflammatory bowel diseases
(IBDs). These illnesses involve inflammation and irritation of the
gastrointestinal (GI) tract. They have many symptoms in common. In some cases,
Crohn’s is difficult to distinguish from ulcerative colitis,
another inflammatory bowel disease. The symptoms of Crohn’s also resemble those
of other GI disorders, such as:
Your doctor will need to perform a physical examination and
obtain information about your medical history. This will include questions
about your family medical history.
Your doctor will want to rule out infection and other GI
There is no single test for Crohn’s disease. The diagnosis
is based on an evaluation of your symptoms and results of a number of tests. If
your symptoms indicate that you might have Crohn’s disease, your doctor will
probably perform a variety of tests.
The following tests will help your doctor determine if you
have Crohn’s disease.
Blood tests will indicate if you have anemia, which might
occur with GI bleeding. The blood tests will also help detect an infection.
Anemia and infections can both occur either with or without Crohn’s disease.
Their presence or absence alone is not enough to provide a diagnosis. Combined
with other test results, blood tests will help your doctor evaluate your exact
You may be asked to supply a stool sample to test for the
presence of blood or signs of infection. The results will be evaluated along
with the results of other tests.
A breath test can identify lactose intolerance. When
undigested lactose is metabolized in the colon, bacteria release hydrogen into
the bloodstream, which can then be measured in your breath. You may have
lactose intolerance with or without Crohn’s disease. However, lactose
intolerance is common with Crohn’s disease. If you have Crohn’s disease and
lactose intolerance, consuming milk and milk products can make your symptoms
A barium enema is an X-ray of the colon, another name for
the large intestine, which includes the rectum. You will undergo this test in a
doctor’s office or a hospital. You will be given an enema using a special
chalky liquid called barium sulfate that coats the large intestine. This allows
for a greater contrast between specific areas and provides clearer X-rays.
An endoscope is a thin, flexible tube with a small camera
mounted on the end. For an upper endoscopy, the doctor will insert the tube
through your mouth to examine the upper portion of your digestive tract, which
includes your mouth, esophagus, stomach, and the first part of your small
intestine, called the duodenum.
Upper GI series
For an upper GI series, the patient drinks barium, and
X-rays are taken of the small intestine.
For a colonoscopy, your doctor will insert an endoscope into
your rectum to examine your entire colon. If a biopsy of the colon lining finds
clusters of inflammatory cells, called granulomas, it will help to confirm a diagnosis
of Crohn’s disease. You may have Crohn’s disease and not have granulomas. You
may also have Crohn’s disease in another part of your digestive tract that
cannot be seen during a colonoscopy.
A sigmoidoscopy is similar to a colonoscopy, but it examines
only the sigmoid colon, the last section of your colon.
During any of the following procedures, your doctor may take
small tissue samples to look at under a microscope.
This is called a biopsy. A biopsy can identify different
types of inflammation and detect cancer or dysplasia, or abnormal cells.
A computed tomography (CT) scan is a special X-ray that uses
computer technology to create a three-dimensional image. You may be asked to
drink a special dye for this procedure. The CT scan helps your doctor assess
the extent and location of disease. It also helps the doctor look for:
- abscesses, or infection
- fistulas, or abnormal tunnels
For this procedure, you will swallow a capsule that contains
a camera with a battery, light, and transmitter. As it works its way through
your digestive system, the camera takes pictures and transmits them to a
computer you wear on your belt. When it has finished its journey, it is passed
in your stool. This procedure is generally very safe. However, if you have an
intestinal blockage, the camera may become stuck and need to be removed
surgically. The pictures taken by this procedure are usually not clear enough for
a final diagnosis.
An MRI uses radio waves and magnetic fields to produce
images of your internal organs. It can help your doctor identify areas of
narrowing and inflammation that are common in Crohn’s disease.
A diagnosis of Crohn’s disease usually requires that you
have certain symptoms, and that results of a combination of the above tests
confirm that diagnosis. An accurate diagnosis is the first step in treating
your illness and relieving your symptoms.