Optimizing Postoperative Nutrition in Colorectal Surgery

2000 mL of peripheral parenteral nutrition with electrolytes (20 mL 7.45% KCl, 10 mL 20% MgSO4 and 20 mL 8.7% Na3PO4) will be administered via a peripheral venous catheter with a rhythm of 80cc/h from the time they will leave the operation room and will be transferred to the ward or the critical care unit (CCU) until the 5th postoperative day