Cases of mediastinal emphysema (pneumomediastinum), as a complication of endoscopic colonoscopy perforation of the colon, according to the publications and given its own experience in the treatment of this rare complication were analyzed. There are few publications on the perforation of the colon during colonoscopy, with the development of pneumomediastinum, pnevmoretroperitoneuma, pneumothorax in a scientific literature. Air supply into the retroperitoneal space and the mediastinum from perforation of the intestine through the place connected with the lifting him through the natural anatomical connection. Some authors provide proven X-ray of the chest clinical cases pneumomediastinum and subcutaneous emphysema in a patient suspected of having ulcerative colitis after outpatient colonoscopy with biopsies, as well as pneumomediastinum with emphysema of soft tissues of the neck after endoscopic polypectomy. The diagnosis was established clinically (dyspnea, subcutaneous emphysema of the neck), but also the data of X-ray studies. The most life-threatening complication of colonoscopy a combination of pneumothorax, pneumomediastinum, and pneumoperitoneum retropnevmoperitoneuma that requires immediate diagnosis and surgical intervention. In these cases, it may be a tension pneumothorax, in which is shown an emergency thoracostomy. During the stress pneumomediastinum an adequate drainage of the mediastinum and (if indicated) pleural cavities is performed. Clinical terms of self-resolution of mediastinal emphysema account for an average of 6.2 days in the majority of patients. During colonoscopy balloon dilation of strictures of the colon may also be complications: subcutaneous emphysema and bilateral pneumothorax. In our practice, there were two clinical cases of mediastinal emphysema at colonoscopy due to perforation of the sigmoid colon in one case, and perforation of the sigmoid colon diverticulum in another. The patients were operated on with a favorable outcome, laparotomy and bowel resection with anastomosis device SEEA-29 were performed. The perforation of the gut during endoscopy requires emergency surgery. Mediastinal emphysema may be as a complication of colonoscopy and is associated with the air intake from the intestine through the perforation into the retroperitoneal space, and then in the mediastinum. During unstressed pnemomediastinume resorption occurs independent of emphysema in the next day after a bowel injury.