Complications of diagnostic colonoscopy, upper endoscopy, and enteroscopy.

Endoscopy is an inherent and an invaluable tool in every gastroenterologist's armamentarium. The prerequisite for quality and safety remains foremost. Adverse events should be minimized and proactive steps should taken before, during and after the endoscopic procedure. Upper endoscopy and colonoscopy are part of basic endoscopy and their major complications will be reviewed here, together with those of enteroscopy. The most common of all endoscopy related complications are cardiopulmonary and thus they will be addressed in detail first. Colonoscopy's major complications are bleeding and perforation. Their epidemiology, mechanisms/risk factors, diagnosis, treatment and prevention will be addressed. The incidence of both of these complications increases significantly with polypectomy. Thus clinical judgment and experience in both polypectomy techniques and the ways to treat these complications, especially with the advanced endoscopic options advanced in the last decade, are of paramount importance. Post-polypectomy syndrome, infection and gas explosion are less frequent and will be reviewed briefly. Bleeding and perforation are upper endoscopy's major complications as well. Advances in endoscopic techniques in recent years offer endoscopic treatment instead of directly resorting to surgery, as was used to be the case and still is if the first fails. Enteroscopy is generally a more advanced procedure and overall complication rate is often quoted as 1%, most of them have been attributed to the passage of the overtube. Perforation and bleeding are the major complications, and a unique upper enteroscopy-associated complication is pancreatitis.