Abstract
Malnutrition is common in surgical patients and is associated with substantially increased morbidity and mortality. Dedicated assessment of nutritional status is advised by major nutrition and surgical societies. Assessment may utilize comprehensive and validated nutritional assessment tools or targeted history, physical examination with accompanying serologic markers to identify nutritional risk preoperatively. Emergent surgery in malnourished patients should proceed as the clinical situation dictates with consideration of ostomy or primary anastomosis with proximal fecal diversion to mitigate postoperative infectious complications. Nonemergent surgery should be delayed to facilitate nutritional optimization via oral nutritional supplementation preferably and total parenteral nutrition if necessary for at least 7 to 14 days. Exclusive enteral nutrition may be considered to optimize nutritional status and inflammation in patients with Crohn's disease. Immunonutrition use in the preoperative setting is not supported by evidence. Perioperative and postoperative immunonutrition may be of benefit but requires dedicated study in the contemporary era. Close attention to preoperative nutritional status and optimization represents a critical opportunity to improve outcomes in patients undergoing colorectal surgery.