 Little data exist in the field of measuring body composition in patients with intestinal failure, where changes in body weight are commonly taken to indirectly measure gastrointestinal absorptive function. Body composition analysis is of particular importance in the management of these patients, since it can help guide medical, surgical andor nutrition interventions, including titration of enteral or parenteral nutrition. To the investigators knowledge there are no studies examining whether air-displacement plethysmography ADP is a valid measure of body composition in patients with intestinal failure. 