Complication Rates in Colonoscopy Screening for Cancer

Screening colonoscopy has been offered in Germany since 2002. Complications during colonoscopy were reported to be rare, but data on potential complications after colonoscopy are sparse. We aimed to comprehensively assess the frequency of complications arising during or within four weeks of screening colonoscopy.

Residents of the German federal state of Saarland without a history of colorectal cancer and without previous polypectomy who underwent a screening colonoscopy between 2010 and 2013 were included. A follow-up was conducted three months after the screening colonoscopy, including participant questionnaires and subsequent validation of self-reported complications arising during or within four weeks of screening colonoscopy, by reviewing colonoscopy records and contacting the treating physicians. A comprehensive mortality follow-up was conducted for non-responders.

We recruited a total of 5527 participants from 26 practices (median age 61 years, 52% women). 5252 (95%) fully completed the questionnaire on complications and met the inclusion criteria for analysis. Among these participants, 16 cases of physician-confirmed bleeding (0.30%) and four cases of physician-confirmed perforation (0.08%) occurred during or within four weeks of colonoscopy. According to consistent reports from patients and physicians, bleeding and perforation led to hospitalization in 5 (0.095%) and 2 (0.04%) cases, respectively. Three participants died within three months of colo - noscopy. In none of these cases was the cause of death related to colonoscopy.

We found the risk of complications of screening colonoscopy to be low, even when taking into account a potential delay of up to four weeks.