Therapy for Crohn's disease has been discussed in practice guidelines published in 2009 7 . These guidelines set up a definition for the severity of a Crohn's disease flare. Mild to moderate disease is indicated when patients can tolerate oral intake without dehydration, high fever, abdominal pain, abdominal mass, or obstruction. Moderate to severe disease describes the disorder in patients who have failed to respond to therapy for mild or moderate disease or those with fevers, weight loss, abdominal pain, anemia, or nausea and vomiting without frank obstruction. Severe to fulminate disease is found in patients with persisting symptoms despite the introduction of steroids on an outpatient basis or those presenting with high fever, persistent vomiting, obstruction, rebound tenderness, cachexia, or an abscess. In addition, it is important to distinguish between differing behaviors of disease: inflammatory, fistulizing, or fibrostenotic because different therapies are best suited for different disease behaviors regardless of disease severity.