The Incidence of 30-Day Adverse Events After Colonoscopy Among Outpatients in the Netherlands

Vincent de Jonge, BSc; Jerome Sint Nicolaas, BSc; Onno van Baalen, MD; Johannes T. Brouwer MD, PhD; Mark F.J. Stolk, MD, PhD; Thjon J. Tang, MD, PhD; Antonie J.P. van Tilburg, MD, PhD; Monique E. van Leerdam, MD, PhD; Ernst J. Kuipers MD, PhD


Am J Gastroenterol. 2012;107(6):878-884. 

In This Article

Abstract and Introduction


Objectives: Colonoscopy is the gold standard for visualization of the colon. It is generally accepted as a safe procedure and major adverse events occur at a low rate. However, few data are available on structured assessment of (minor) post-procedural adverse events.
Methods: Consecutive outpatients undergoing colonoscopy were asked for permission to be called 30 days after their procedure. A standard telephone interview was developed to assess the occurrence of (i) major adverse events (hospital visit required), (ii) minor adverse events, and (iii) days missed from work. Adverse events were further categorized in definite-, possible-, and unrelated adverse events. Patients were contacted between January 2010 and September 2010.
Results: Out of a total of 1,528 patients who underwent colonoscopy and gave permission for a telephone call, 1,144 patients were contacted (response: 75%), 49% were male, the mean age was 59 years (s.d.: 14). Thirty-four patients (3%) reported major adverse events. These were definite-related in nine (1%) patients, possible-related in 6 (1%), and unrelated in 19 patients (2%). Minor adverse events were reported by 466 patients (41%). These were definite-related in 336 patients (29%), possible-related in 36 (3%), and unrelated in the remaining 94 patients (8%). Female gender (odds ratio (OR): 1.5), age <50 years (OR: 1.5), colonoscopy for colorectal cancer screening/surveillance (OR: 1.6), and fellow-endoscopy (OR: 1.7) were risk factors for the occurrence of any definite-related adverse event. Patients who reported definite-related adverse events were significantly less often willing to return for colonoscopy (81 vs. 88%, P<0.01) and were less often positive about the entire colonoscopy experience (84 vs. 89%, P=0.04).
Conclusions: Structured assessment of post-colonoscopy adverse events shows that these are more common than generally reported. Close to one-third of patients report definite-related adverse events, which are major in close to 1 in 100 patients. The occurrence of adverse events does have an impact on the willingness to return for colonoscopy.


Colonoscopies are responsible for >50% of all endoscopic procedures performed per year in the United States.[1] In 2002, it was estimated that over 14 million colonoscopies were performed in the United States.[2] The total volume of colonoscopies has consistently expanded since then and will further increase in the coming years.[3,4]

In general, colonoscopy is a safe procedure, but a small number of major adverse events do occur. The most serious adverse event is procedure-related death. A Canadian population-based cohort study showed that colonoscopy-related mortality 30 days after the procedure was 0.007%.[5] Other major adverse events include perforation (0.07%) and bleeding (0.16%) after colonoscopy.[5,6] The most common adverse events are sedation related, in particular cardiopulmonary events. These adverse events have been reported to occur in >1% of colonoscopies.[7,8] Furthermore, case reports described sporadic complications such as splenic rupture and colonic explosion.[9,10]

Most adverse events occur at the endoscopy unit. However, adverse events can also occur in the days after the procedure. The incidence of major adverse events in the days after a colonoscopy is insufficiently clear.[11–13] Furthermore, few data are available on the occurrence of minor adverse events. It has been suggested that up to 30% of patients experience minor adverse events.[11,14,15] The occurrence of these minor adverse events may have an impact on the willingness to return for colonoscopy. This loss of adherence and the potential negative advice to others to undergo colonoscopy impair the effectiveness of colorectal cancer screening and surveillance.[16]

The aim of this study was to systematically assess the rate of both major and minor adverse events in the 30 days after colonoscopy.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: