Understanding Crohn’s disease

What is Crohn’s disease?

Crohn’s is one of a group of disorders collectively referred to as “inflammatory bowel disease” (IBD). Crohn’s causes painful inflammation in your digestive tract and usually occurs in the lower part of the small intestine or colon.

What causes Crohn’s disease?

While the direct cause of Crohn’s is unknown, here’s what we do know: First, you may be more likely to experience Crohn’s if it’s part of your family’s medical history. Second, Crohn’s symptoms begin when your immune system attacks healthy cells in your body, for reasons we do not yet understand.

Normally, the immune system (the body’s natural defense system) protects your body from bacteria, viruses, and other foreign agents. When you have Crohn’s, your immune system incorrectly targets your GI tract. This causes inflammation, leading to the symptoms and flares usually experienced with Crohn’s.

Who gets Crohn’s disease?

Approximately 500,000 Americans have crohn's disease which affects men and women equally.
  • Crohn's seems to run in families—20%-25% of people with Crohn's have a close relative with some form of IBD

  • Crohn's most often appears in people between the ages of 15 and 30, although it may occur at any age

  • People of Caucasian and Jewish origins have a higher risk of developing IBD compared with other racial and ethnic subgroups

Hear from actual patients with moderately to severely active Crohn’s who didn’t respond well to other therapies and were treated with REMICADE®.
Individual results may vary.


The most common symptoms of Crohn’s include:

  • Abdominal pain
  • Fever
  • Cramping
  • Rectal bleeding
  • Frequent diarrhea

Other symptoms may include:

  • Loss of appetite
  • Weight loss

Fistulas are another symptom to be aware of. Fistulas occur when the inflammation and ulcers caused by Crohn’s break through the intestinal wall and form an abscess (or a tunnel) outside of it.

How is Crohn’s diagnosed?

Although there is no cure for Crohn’s, the sooner Crohn’s is diagnosed, the sooner you may be able to gain control of your symptoms and possibly induce remission.

To confirm a diagnosis—and to rule out other conditions that can cause similar symptoms—your physician will probably perform a complete physical exam and order medical tests. There is no single test that can confirm the diagnosis of Crohn’s.

Diagnostic tests may include:

  • Blood tests: These tests can provide your gastroenterologist with information that will help assess your overall condition
  • Examinations: These exams help your gastroenterologist see inside your body to determine whether you have Crohn’s. Different types of tests include:
    • Barium enema: This test helps gastroenterologists examine the colon and the rectum
    • Upper GI and small bowel follow-through: In this test, X-rays help doctors examine the esophagus, stomach, duodenum, and small intestine
    • Enteroclysis: This test is used to reveal abnormalities in the small intestine
    • Computerized tomography (CT) scan: This detailed scan is used to detect abnormalities
    • Ultrasound: By using sound waves, this test examines organs of the pelvis and abdomen without exposure to radiation and is often used in combination with other radiologic tests
    • Magnetic resonance imaging (MRI): By using radio waves and superconducting magnets, this test can help detect fistulas and abscesses
    • Stool tests: These noninvasive tests examine stool samples to determine the possibility of bacterial, viral, or parasitic causes of diarrhea
    • Urine tests: Also called urinalysis, these tests are used to detect the presence of bacteria, red blood cells, and white blood cells in your urine
    • Endoscopic examinations: These tests use a tool called an endoscope to get a detailed view of the intestinal tract. Different endoscopic exams may include: sigmoidoscopy, colonoscopy, and upper endoscopy

It's important to discuss all your symptoms with your doctor to determine the appropriate tests.

Crohn’s and ulcerative colitis

Crohn’s and ulcerative colitis (UC) are classified as types of IBD, a term used to describe inflammatory conditions affecting the digestive (or gastrointestinal [GI]) tract.

While Crohn’s and UC are both IBDs and have similar symptoms, there are a few distinct differences between the 2 conditions:


REMICADE® can lower your ability to fight infections. Serious and sometimes fatal events can occur. There have been reports of serious infections including tuberculosis (TB) and infections caused by bacteria, fungi, or viruses that have spread throughout the body. Lymphoma, including a fatal kind called hepatosplenic T-cell lymphoma, and other cancers have been reported in children and adults taking REMICADE®. Some people with heart failure should not take REMICADE®. Other serious side effects reported include skin cancer, hepatitis B, liver injury, blood problems, allergic reactions, nervous system problems, or lupus-like syndrome. To learn more about these and other risks, please read the Important Safety Information and the Medication Guidepdf, and talk with your doctor.

Download the Medication Guidepdf to learn more about REMICADE®. (Requires Adobe® Reader®. Click here to download.)

Next: Treatment options NEXT: Treatment Options


REMICADE® is a prescription medication used to treat:

Crohn's Disease
  • Can reduce signs and symptoms and induce and maintain remission in adult patients with moderately to severely active Crohn’s disease who haven't responded well to other therapies
Pediatric Crohn's Disease
  • Can reduce signs and symptoms and induce and maintain remission in children (ages 6-17) with moderately to severely active Crohn's disease who haven't responded well to other therapies
Ulcerative Colitis
  • Can reduce signs and symptoms, induce and maintain remission, promote intestinal healing, and reduce or stop the need for steroids in adult patients with moderately to severely active ulcerative colitis who haven't responded well to other therapies
Pediatric Ulcerative Colitis
  • Can reduce signs and symptoms and induce and maintain remission in children (ages 6-17) with moderately to severely active ulcerative colitis who haven’t responded well to other therapies
Rheumatoid Arthritis
  • Can reduce signs and symptoms, help stop further joint damage, and improve physical function in patients with moderately to severely active rheumatoid arthritis, in combination with methotrexate
Psoriatic Arthritis
  • Can reduce signs and symptoms of active arthritis, help stop further joint damage, and improve physical function in patients with psoriatic arthritis
Ankylosing Spondylitis
  • Can reduce signs and symptoms in patients with active ankylosing spondylitis
Plaque Psoriasis
  • Approved for the treatment of adult patients with chronic severe (extensive and/or disabling) plaque psoriasis under the care of a physician who will determine if REMICADE® is appropriate considering other available therapies


Only your doctor can recommend a course of treatment after checking your health condition. REMICADE® (infliximab) can cause serious side effects such as lowering your ability to fight infections. Some patients, especially those 65 years and older, have had serious infections caused by viruses, fungi or bacteria that have spread throughout the body, including tuberculosis (TB) and histoplasmosis. Some of these infections have been fatal. Your doctor should monitor you closely for signs and symptoms of TB during treatment with REMICADE®.

Unusual cancers have been reported in children and teenage patients taking TNF-blocker medicines. Hepatosplenic T-cell lymphoma, a rare form of fatal lymphoma, has occurred mostly in teenage or young adult males with Crohn’s disease or ulcerative colitis who were taking REMICADE® and azathioprine or 6-mercaptopurine. For children and adults taking TNF blockers, including REMICADE®, the chances of getting lymphoma or other cancers may increase.

You should discuss any concerns about your health and medical care with your doctor.

What should I tell my doctor before I take REMICADE®?

You should let your doctor know if you have or ever had any of the following:

  • Tuberculosis (TB) or have been near someone who has TB. Your doctor will check you for TB with a skin test. If you have latent (inactive) TB, you will begin TB treatment before you start REMICADE®.
  • Lived in a region where certain fungal infections like histoplasmosis or coccidioidomycosis are common.
  • Infections that keep coming back, have diabetes or an immune system problem.
  • Any type of cancer or a risk factor for developing cancer, for example, chronic obstructive pulmonary disease (COPD) or had phototherapy for psoriasis.
  • Heart failure or any heart condition. Many people with heart failure should not take REMICADE®.
  • Hepatitis B virus (HBV) infection or think you may be a carrier of HBV. Your doctor will test you for HBV.
  • Nervous system disorders (like multiple sclerosis or Guillain-Barré syndrome).

Also tell your doctor if you:

  • Use the medicines Kineret (anakinra), Orencia (abatacept) or Actemra (tocilizumab) or other medicines called biologics used to treat the same problems as REMICADE®.
  • Are pregnant, plan to become pregnant, are breast-feeding, or have a baby and were using REMICADE® during your pregnancy. Tell your baby's doctor about your REMICADE® use. If your baby receives a live vaccine within 6 months after birth, your baby may develop infections with serious complications that can lead to death.
  • Recently received or are scheduled to receive a vaccine. Adults and children taking REMICADE® should not receive live vaccines or treatment with a weakened bacteria (such as BCG for bladder cancer) while taking REMICADE®.

What should I watch for and talk to my doctor about before or while taking REMICADE®?

The following serious (sometimes fatal) side effects have been reported in people taking REMICADE®.

You should tell your doctor right away if you have any of the signs listed below:

  • Infections (like TB, blood infections, pneumonia)—fever, tiredness, cough, flu, or warm, red or painful skin or any open sores. REMICADE® can make you more likely to get an infection or make any infection that you have worse.
  • Lymphoma, or any other cancers in adults and children.
  • Skin cancer—any changes in or growths on your skin.
  • Heart failure—new or worsening symptoms, such as shortness of breath, swelling of your ankles or feet, or sudden weight gain.
  • Reactivation of HBV—feeling unwell, poor appetite, tiredness, fever, skin rash and/or joint pain.
  • Liver injury—jaundice (yellow skin and eyes), dark brown urine, right-sided abdominal pain, fever, or severe tiredness.
  • Blood disorders—fever that doesn’t go away, bruising, bleeding or severe paleness.
  • Nervous system disorders—numbness, weakness, tingling, changes in your vision or seizures.
  • Allergic reactions during or after the infusion—hives, difficulty breathing, chest pain, high or low blood pressure, swelling of face and hands, and fever or chills.
  • Lupus-like syndrome—chest discomfort or pain that does not go away, shortness of breath, joint pain, rash on the cheeks or arms that gets worse in the sun.
  • Psoriasis—new or worsening psoriasis such as red scaly patches or raised bumps on the skin that are filled with pus.

The more common side effects with REMICADE® are respiratory infections (that may include sinus infections and sore throat), headache, rash, coughing and stomach pain.

Please read the Medication Guide for REMICADE® and discuss it with your doctor. (Requires Adobe® Acrobat® Reader®. Click here to download.)

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit www.fda.gov/medwatch, or call 1-800-FDA-1088.