An infusion center is an outpatient clinic that is certified to administer infusion therapy. These medical facilities have advanced equipment and competent staff who specialize in infusions. Infusion therapy is usually employed to treat serious or chronic infections that do not respond to oral antibiotics. Cancers and the pain caused by cancers; diseases of the gastrointestinal tract; dehydration caused by nausea, vomiting and diarrhea; and other serious diseases, such as Crohn's disease, are typical examples. Additional complex illnesses that respond best to intravenous medications include: multiple sclerosis, some forms of arthritis, congestive heart failure and some types of immune deficiency disorders. Certain congenital diseases require intravenous medications as well.