Background: Minor complications in colonoscopy, such as pain, distension, headache, dizziness, etc. are an important cause for the rejection of colonoscopy procedure. Their incidence, however, has not been established.
Objective: To determine minor complication rates in outpatient colonoscopy procedures and the effect of sedation on these complications.
Patients: A prospective randomized cohort study was performed on 1250 adults selected randomly among patients referred to our endoscopy unit. Complications and undesirable affects related to the colonoscopy were reordered during the patients' stay in the endoscopy unit (early complications) and 30 days postprocedure (late complications).
Results: One thousand one hundred and twenty-six patients were enrolled (mean age 50.43+/-13.7 years; 54.5% female), of which 875 (78%) were sedated and 251 (22%) were not. No difference between groups was observed. Thirty-one percent of the patients had early minor complications (25% among sedated patients; 52% of nonsedated patients; P<0.001 chi2); 23% had late minor complications (16% of sedated patients vs. 51% nonsedated patients; P<0.001 chi2). The most common undesirable effects were pain and abdominal distension. The risk of experiencing complications - odds ratio - was 1.013 times higher per year of age [confidence interval (CI) 95%: 1.004-1.022]; 1.953 times higher per increase in American Society of Anesthesiologists classification (95% CI: 1.524-2.504); and 0.116 times lower when sedation was used (95% CI: 0.079-0.170).
Conclusion: Minor complications of colonoscopy are common. Their incidence increases with age and American Society of Anesthesiologists class and decreases with the use of sedation.