Since colonscopy is more and more spreading, because of screening diagnostic procedures, it is important to know which can be its complications. Some Californian researchers examined electronic medical records of 16.318 screening colonscopies performed on symptomatic patients. Complications (among which bleeding, intestinal perforations, diverticulitis) were identified through hospitalizations or death occurred within 30 days from colonscopy. The most frequent indication to perform the exam was represented by the detection of polyps through sigmoidoscopy (45% of cases, almost everyone together with biopsy) or from a history of previous polyps (23%, with biopsy in half cases), while only 7%was represented by primary screening. The overall incidence of severe complications was of 5%. Among the 5235 colonscopies which were not performed together with biopsy, severe complications had an incidence of 0,8‰ (0.6‰ of perforations); among the 11.083 colonscopies with biopsy, severe complications had an incidence of 7‰ (4.8‰ of bleeding with the need of surgery or transfusion). The risk of intestinal perforation was higher in subjects of 60 or more. Performing an overall analysis, 40% of all severe complications and 64% of all bleedings occurred after endoscopic removal of polups smaller than 10 mm.
The cumulative incidence of severe complications was, at least in this study, of about 1 out of 200 examinations, which is not little for a screening procedure theoretically destined to lots of people. It is necessary to underline that in this trial, colonscopy was performed not as a screening on healthy subjects but prevalently under clinical indications, with the performance of very frequent biopsies. But it is however true that the risk of perforation and of severe bleeding is high, so undergoing this procedure must be the result of an informed and well thought choice by physician and patient.
