Laparoscopy systems possess remarkable heat production. Video-laparoscopy was used for colonoscopy intraoperatively in rabbits. Rod lens type laparoscopes 5 and 10 mm in diameter connected with 175 and 300-W xenon light sources were used in combination. Physiological parameters including blood pressure, pulse, oxygen saturations, and luminal temperatures were investigated during 20 minutes of colonoscopy. Thermal damage scores were obtained by histopathologic analysis of the intestinal wall. The changes were categorized as physiological and structural. Damage scores were not different when 175-W light source was used with 5- and 10-mm laparoscopes. Intraluminal heat values most increased with 300 W plus 10-mm laparoscope and caused significant increase in damage scores. Structural damage indicating tissue necrosis was not observed with any of the combination in all groups. Video-laparoscopy systems did not cause significant tissue damage when used at low and moderate levels of xenon light source in the rabbit bowel intraoperatively.