Omegaven is an intravenous fat emulsion (IFE) comprised of omega-3 fatty acids derived from fish oil. It will be used in an open label compassionate use treatment protocol, as an alternative to soybean oil (omega-6), as the sole IFE source of parenteral nutrition in an effort to reduce and/or reverse parenteral nutrition associated liver disease. The study will evaluate the safety and efficacy of Omegaven use in pediatric patients with PN dependence and PNALD.