Adolescent Adult Aged Aged, 80 and over Anastomosis, Surgical Anti-Infective Agents, Local--administration & dosage Body Mass Index Child Child, Preschool Colorectal Surgery Equipment Contamination--prevention & control Equipment and Supplies, Hospital Female Humans Infection Control--methods Intestines--surgery Intraoperative Care Isotonic Solutions Male Middle Aged Multivariate Analysis Operating Rooms Patient Care Team Povidone-Iodine--administration & dosage Prospective Studies Protective Devices Ringer's Solution Risk Factors Sterilization Surgical Wound Infection--prevention & control Temperature Time Factors