The randomized study to evaluate whether the instruments for clearing laparoscope reduce the surgical stress in colorectal cancer surgery.

Interventions: Clearing lens of laparoscope using the warm saline and gaze
Clearing lens of laparoscope using the instrument for clearing lens of laparoscope (OpClear)
Primary outcome(s): To evaluate whether instruments for clearing lens of laparoscope reduce the multifaceted surgical stress in the colorectal operation.
Study Design: Parallel Randomized