The routine bowel preparation before colorectal surgery usually includes mechanical and medicine preparations, with the original purpose of reducing complications such as anastomosis leakage, wound, and abdominal infections. Many domestic hospitals are still employing the methods of three-day bowel preparation, while in the West, the way of this preparation has dramatically changed. In last decade, one-day preparation has been widely accepted internationally, with two major medications of sodium phosphate and polyethylene glycol frequently used in the clinic. It has also been indicated that excessive mechanical and medicinal bowel preparations exert harmful effects on the combined intestinal barrier, and may result in various complications. A few reports have suggested to omit the mechanical bowel preparation before surgery, which is still under controversy, however, well-designed clinical trials are needed to readjust and regulate the duration and intensity of bowel preparation before colorectal surgery in China.