There has been a growing need to utilize the concept of "precision medicine" in the treatment of inflammatory bowel disease (IBD). In practice, precision medicine for IBD comprises prediction and personalizing therapies. Prediction is divided into two subcategories: pre-treatment investigation and monitoring response to therapy. Pre-treatment prediction includes clinical outcome assessment, investigation of factors for poor outcome, magnetic resonance enterography, and measurement of TPMT, NUDT15, and other biologic markers. Mucosal healing or transmural healing is considered the "treat-to-target" approach in IBD. To achieve "treat-to-target," the "top-down strategy" is recommended in patients with pediatric Crohn's disease, because the therapeutic window of opportunity may be shorter than that generally believed. We are unable to state that we are truly utilizing biologics in a perfect manner until both "treat-to-target" and "top-down strategy" are supported by "therapeutic drug monitoring (TDM)," a key component of personalizing therapy for IBD. Proactive TDM, or more precisely, model-based proactive dosing with point-of-care assay will soon emerge as the new standard for IBD treatment. It is speculated that "treat-to-target," "top-down strategy," and "TDM" may aid personalized therapy to achieve outstanding improvement in patients with pediatric IBD.