Wendy: I found this.
4.1.2 Q: What is total parenteral nutrition?
Total parenteral nutrition (TPN), or hyperalimention, delivers a concentrated solution of nutrients intravenously. This is used in very active disease either giving it time to subside, or to nourish the patient before surgery.
People with Crohn's Disease generally benefit more than those with UC because CD usually affects the small intestine, which is where nutrients are absorbed. TPN may, however, occasionally be warranted in critically ill people with UC.
Richard