Randamized control trial for the effect of preoperative carbohydrate loading on the post operative hyperglycemia and evaluatioin of time to eliminate gastric contents on the patients with colorectal cancer surgery

Interventions: The control group: At preoperative night, patient drinks 800mL of water. From 2.5 to 3 hours before operation, patients drink 400mL of water.
The 12.5% of carbohydrate group: At preoperative night, patient drinks 800mL of 12.5% of carbohydrate. Before 2.5 to 3 hours to operation, patients drink 400mL of 12.5% of carbohydrate.
The 16.7% of carbohydrate group: At preoperative night, patient drinks 600mL of 16.7% of carbohydrate. From 2.5 to 3 hours before operation, patients drink 300mL of 16.7% of carbohydrate.
Primary outcome(s): Improvement of insulin resistance pre- and post- operation with HOMA-R Blood glucose Concentration of blood insulin
Study Design: Parallel Randomized