Patients with inflammatory bowel disease (IBD) who require methotrexate (MTX)for treatment currently receive this drug by injection. MTX is also available as a pill that can be given by mouth but it is not known how well the drug enters the body in patients with Crohn's disease or ulcerative colitis. This study is being done to compare how much MTX enters the body when the drug is taken by mouth compared to when it is given by injection. If the drug is well absorbed, it may allow patients to receive the drug by mouth.