Tehran University of Medical Sciences Acta Medica Iranica 0044-6025 55 7 2017 09 16 477 479 EN Hossein Parsa Department of Surgery, Velayat Hospital, Qazvin University of Medical Sciences, Qazvin, Iran. Arash Miroliaee Department of Internal Medicine, Velayat Hospital, Qazvin University of Medical Sciences, Qazvin, Iran. Zafar Doagoo Department of Internal Medicine, Zakariya-e-Razi Hospital, Qazvin, Iran. Saeed Sina Department of Surgery, Velayat Hospital, Qazvin University of Medical Sciences, Qazvin, Iran. 2015 12 28 2016 05 23 Colonoscopy is widely used for the diagnosis, treatment and a follow up of colorectal diseases. Perforation of the large bowel during elective colonoscopy is rare but serious life threatening complication. We report a 51-year-old woman who experienced recto sigmoid perforation during diagnostic colonoscopy. During 8 days of total hospitalization, she spent 3 days in ICU with gastrointestinal rest. The patient was hydrated and took intravenous antibiotics. In take-output and temperature were closely monitored. Serial abdominal examinations were performed to rule out peritonitis. After transferring to surgery ward in the day 4, liquid diet started slowly, and she was ambulated. At the day 8, she was discharged with the good clinical condition. Conservative management of the patients with early diagnosis of perforation and no signs and symptoms of peritonitis or sepsis could be the modality of choice. https://acta.tums.ac.ir/index.php/acta/article/view/5319 https://acta.tums.ac.ir/index.php/acta/article/download/5319/4968