Disease Summary:

Crohn's disease (CD) is a chronic inflammatory disease of the gastrointestinal (GI) tract.  It can occur anywhere in the GI tract from the mouth to the anus, but it occurs primarily in the small intestine and colon.  Crohn's disease effects all layers of the bowel wall, whereas ulcerative colitis effects the innermost lining of the colon.  Crohn's disease can involve different parts of the GI tract in a continuous or patchy distribution.

 

In Crohn's disease, it is thought the immune system becomes abnormally active against an individual's own gastrointestinal tract.  The exact cause is not known, but it is thought to be a result of a complex interaction between one's genetic make-up, their immune system, and environmental factors.  Crohn's disease occurs equally in men and women with symptoms usually starting between the ages of 15 and 35.  However, it can occur at any time during one's lifetime.  Crohn's disease can occur in families, but 80% of individuals with Crohn's disease do not have a genetic predisposition.  Individuals with CD who smoke tend to have a more severe form of the disease and are at higher risk of requiring surgery.

 

Symptoms depend upon the severity and location of the inflammation.  They can range from none or mild to severe, and may occur gradually or come on suddenly without warning.  Abdominal pain, persistent diarrhea, blood in the stool, fever, and unexplained weight loss are symptoms of CD.  Mouth ulcers, nausea and vomiting, joint pain, skin disorders, and eye inflammation may also occur in CD.

 

Multiple tests are usually required to confirm the diagnosis.  A colonoscopy is performed to directly visualize the colon and lower small intestine (terminal ileum) and obtain biopsies (small pieces of tissue) for microscopic examination.  Radiologic tests include CT scan, MRI, upper gastrointestinal series with small bowel follow-through, and capsule endoscopy (pill camera study) may be performed to assess the extent and severity of the disease.  Special blood tests may also be performed.  Because CD effects all layers of the lining of the GI tract, fistulas and abscesses may occur.  Fistulas are abnormal connections between the GI tract and other parts of the GI tract, or other parts of the body.  Individuals may also develop bowel obstruction as a result of the inflammation and scarring, which blocks the flow of digested contents through the GI tract.

 

Medical treatment involves healing the inflammation and maintaining remission, or preventing the inflammation from returning.  Medications include aminosalicylates, steroids, immunomodulators, and biologics.  There is no cure for CD, but medication can significantly reduce symptoms and even bring about long-term remission.

 

Aminosalicylates (sulfasalazine and mesalamine) are antiinflammatory drugs used to treat mild to moderate symptoms.  The medications are available in oral and rectal formulations and work to decrease inflammation in the gastrointestinal tract.  Other antiinflammatory medications such as ibuprofen, naproxen, and diclofenac should be avoided because they may cause worsening of symptoms.

 

Corticosteroids (prednisone, methylprednisolone, and budesonide) are used to treat moderate to severe CD and are available in oral, IV (intravenous), and rectal formulations.  Corticosteroids have a number of significant side effects, and are not intended for chronic (long-term) use to maintain remission.  Budesonide has fewer side effects and may be used long-term. Your doctor will discuss other potential side effects from these medications.

 

Immunomodulator medications include 6-mercaptopurine (6-MP), azathioprine, and methotrexate.  These medications are taken orally, but may take up to two to three months to reach their peak effect.  Methotrexate may be given initially with weekly subcutaneous (SQ) injections.  These medications are effective for maintenance of remission in moderate to severe disease.  Periodic blood work is required because these medications may cause a low white blood cell count and liver test abnormalities.  Your doctor will discuss other potential side effects from these medications.

 

Biologic agents are given by injection to treat and maintain remission in moderate to severe Crohn's disease.  The medication can be given IV (intravenous) or SQ(subcutaneous) depending upon the particular drug.  These medications suppress the immune system and one should be checked for tuberculosis and hepatitis B prior to starting therapy.  These medications are effective in maintaining long-term remission.  There are rare risks of serious infections with these medications.  Your doctor will discuss other potential side effects from these medications.

 

It does not matter which medication you are taking, medication compliance is essential.  If medication is not taken properly, the result may be recurrence or worsening of symptoms and the development of additional complications.  This may require escalation of therapy or possibly surgery.  Medication adherence and maintaining follow-up with your doctor will help minimize these risks.

 

At some point surgery may be required.  This occurs when medications no longer control symptoms or inflammation, or if complications develop.  These complications include intestinal obstruction, abscess or fistula formation, or perforations (rupture) of the bowel.

​

For More Information Go To These Websites:

​

gastro.org

gi.org

niddk.nih.gov

​

​