Inclusion Criteria:

• Male and female children between the ages of six and eighteen years of age with recurrence of active Crohn's disease, determined by their primary pediatric gastroenterologist to require either:

  1. Corticosteroid therapy ((1-2 mg/kg/d up to maximum of 60 mg/day) with taper, or
  2. Infliximab therapy (5 mg/kg at 0, 2, and 6 weeks, followed by q 8 week therapy)
• Crohn's disease of at least 3 months since diagnosis, with gastritis, duodenitis, ileitis, ileocolitis, or colitis, confirmed by endoscopy and biopsy
• PCDAI score >20

• If receiving concomitant medications, must have been on a stable regimen as follows:

  1. Subjects on aminosalicylates and/or immunomodulators should be on a stable dose for at least 2 weeks prior to enrollment.
  2. Subjects must be off oral, rectal, and parenteral corticosteroids at least 2 weeks prior to enrollment.

• Screening laboratory tests that meet the following criteria (obtained within 4 weeks of enrollment):

  1. Hemoglobin >8.0 g/dL
  2. White blood cell count >3.5 x 109/L
  3. Neutrophils >1.5 x 109/L
  4. Platelets >100 x 109/L
  5. Aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase levels within 3 times the upper limit of normal.
• For those patients to receive infliximab, PPD skin tests with skin induration <5 mm.
• Signed written consent from the parent/legal guardian and assent from the child to be obtained prior to enrollment.

Exclusion Criteria:

• Local manifestations of Crohn's disease, including fistula(s), strictures, abscesses, or other complications for which surgery may be indicated.
• Surgery for bowel diversion with placement of stoma within 3 months prior to screening.
• Positive stool examination of enteric pathogens including Salmonella and Shigella species, Clostridium difficile, and Giardia lamblia.
• Female subjects who are pregnant, nursing, or planning pregnancy.
• Concomitant diagnosis or history of congestive heart failure.
• Treatment with parenteral nutrition within 4 weeks of enrollment.
• Serious infection in the 3 months prior to enrollment.
• History of prior or current active or latent tuberculosis.
• Immune deficiency syndrome, including documented human immunodeficiency virus (HIV) or acquired immunodeficiency syndrome (AIDS).
• History of systemic lupus erythematosus.
• A transplanted organ.
• Known malignancy or history of malignancy within 5 years of enrollment.
• History of demyelinating disease.
• History of substance abuse.
• Poor tolerability of venipuncture or lack of venous access during the study period.
• A live virus vaccination within 3 months of enrollment.
• Prior history of infliximab infusion, or any other therapeutic agent targeted at reducing tumor necrosis factor-a (TNF-a).
• Hypersensitivity to any murine proteins or other component of infliximab for those patients to receive infliximab.
• Inability to comply with study procedures