When the nutritional needs of the patient cannot be met solely by the enteral route, parenteral nutrition is indicated. Parenteral nutrition can be used to provide all nutrients IV (total - TPN) or in combination with some enteral feedings (partial - PPN). The common diagnoses related to a non- or poorly-functioning GI tract include: functional immaturity of the GI tract surgical GI disorders short bowel syndrome malabsorption intractable diarrhea of infancy necrotizing enterocolitis pharmacologic paralysis Not all patients with the above conditions will require TPN. Additional criteria to consider for the use of TPN are that the patient is already malnourished and/or will need to remain NPO for an extended period of time - 1-3 days for newborns and infants and 3-5 days for previously well-nourished pediatric patients.