Crohn’s Disease

What is Crohn’s disease?

Crohn’s disease occurs when there is redness and swelling (inflammation) and sores along your digestive tract. It is part of a group of diseases known as inflammatory bowel disease or IBD.

Crohn’s disease is a long-term, chronic illness that may come and go at different times in your life. In most cases, it affects the small intestine, most often the lower part called the ileum. In some cases, it affects both the small and large intestines.

Sometimes the inflammation may be along your whole digestive tract. This includes your mouth, your food pipe (esophagus), your stomach, the first part of your small intestine or duodenum, your appendix, and your anus. 

What causes Crohn’s disease?

Experts don’t know what causes Crohn’s disease. It may be that a virus or a bacteria affects the body’s infection-fighting system (immune system). The immune system may create an abnormal inflammation reaction in the intestinal wall that does not stop.

Many people with Crohn’s disease have abnormal immune systems. But experts don’t know if immune problems cause the disease. They also don’t know if Crohn’s disease may cause immune problems. Stress does not seem to cause Crohn’s disease.

Who is at risk for Crohn’s disease?

Crohn’s disease may happen at any age. It most often affects people ages 15 to 35. It
can also happen in children or older adults. It affects men and women equally.

You may be more at risk for Crohn’s disease if you:

  • Have a
    family history of Crohn’s disease, such as your father, mother, brother, sister, or
  • Have an Eastern European background, especially Jews of European descent
  • Are white
  • Live in a developed country, in a city, or in a northern climate
  • Smoke

What are the symptoms of Crohn’s disease?

Each person’s symptoms may vary. Symptoms may include:

  • Belly or abdominal pain, often in the lower right area
  • Diarrhea, sometimes bloody
  • Rectal bleeding
  • Weight loss
  • Fever
  • Joint pain
  • Nausea
    or vomiting
  • A cut or tear in the anus (anal fissure)
  • Rashes

You may have no symptoms for a long time, even years. That is called being in remission. There is no way to know when remission may occur or when your symptoms will return.

The symptoms of Crohn’s disease may look like other health problems. Always see your healthcare provider to be sure.

How is Crohn’s disease diagnosed?

You may be checked for signs of Crohn’s disease if you have had long-term or chronic:

  • Belly or abdominal pain
  • Diarrhea
  • Fever
  • Weight loss
  • Anemia, a loss of healthy red blood cells that can make you feel tired

Your healthcare provider will look at your past health and give you a physical exam.

Other tests for Crohn’s disease may include the following:

  • Blood
    These are done to see if you have fewer healthy red blood cells
    (anemia) because of a loss of blood. These tests also check if you have a higher
    number of white blood cells. That might mean you have an inflammatory problem.
  • Stool
    This is done to see if you have any abnormal bacteria in your
    digestive tract that may cause diarrhea or other problems. A small sample of your
    stool is collected and sent to a lab. In 2 or 3 days the test will show if you have
    abnormal bacteria or if you have lost blood. It will also show if an infection by a
    parasite or bacteria is causing your symptoms.
  • Other stool tests. Besides a stool
    culture, other stool sample tests like a fecal calprotectin may be done to see if
    there is inflammation in your intestine.
  • Upper
    endoscopy (EGD).
    This test looks at the inside of your food pipe or
    esophagus, stomach, and the top part of your small intestine, called the duodenum.
    This test uses a thin, lighted tube, called an endoscope. The tube has a camera at
    one end. The tube is put into your mouth and throat. Then it goes into your
    esophagus, stomach, and duodenum. Your healthcare provider can see the inside of
    these organs. They can also take a small tissue sample or biopsy if needed.
  • Colonoscopy. This test looks at the full length of your large intestine. It
    can help check for any abnormal growths, tissue that is red or swollen, sores, or
    bleeding. A long, flexible, lighted tube called a colonoscope is used. It is put into
    your rectum up into the colon. This tube lets your healthcare provider see the lining
    of your colon and take out a tissue sample or biopsy to test it. They may also be
    able to treat some problems that may be found.
  • Biopsy.
    Your healthcare provider will take a tissue or cells from the lining of your colon to
    look at it under a microscope.
  • Upper GI
    series or barium swallow.
    This test looks at the organs of the top part of
    your digestive system. It checks your esophagus, stomach, and the first part of your
    small intestine, called the duodenum. You will swallow a chalky fluid called barium.
    Barium coats the organs so that they can be seen on an X-ray. Then X-rays are taken
    to check your digestive organs. 
  • Lower GI
    series or barium enema.
    This test checks your large intestine, including the
    colon and rectum. A thick, chalky fluid called barium is put into a tube. It is
    inserted into your rectum as an enema. Barium coats the organs, so they can be seen
    on an X-ray. An X-ray of your belly will show any narrowed areas called strictures.
    It will also show any blockages or other problems.
  • CT scan.
    This test uses X-ray images to create a view of the intestine. It may be done with an
    IV and oral contrast.
  • MRI.
    This test uses a magnetic field and radio waves to create a view of the abdomen,
    pelvis, and intestine. It may be done with IV contrast, and in some cases, rectal
  • Capsule endoscopy. For this test, you
    swallow a small pill (capsule) that is a video camera. It takes pictures of the small
    intestine. The capsule is passed naturally, and pictures from the monitor are
    evaluated on a computer.