Background and Aims: Patients undergoing colonoscopy are often in the workforce. Therefore, colonoscopy may affect patients’ work productivity in terms of missed working days and/or reduced working efficiency. We aimed to investigate the impact of colonoscopy on work productivity and factors influencing this impact. Methods: We conducted a prospective, observational, multicenter study in 10 Italian hospitals between 2016 and 2017. We collected information on individual characteristics, work productivity, symptoms, and conditions before, during, and after the procedure from patients undergoing colonoscopy for several indications using validated tools. Outcomes were interference of preparation with work, absenteeism, and impaired work performance after the procedure. We fitted multivariate logistic regression models to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for potential predictors of the outcomes. Results: Among 1137 subjects in the study, 30.5% reported at least 1 outcome. Impaired work performance was associated with bowel preparation regimen (full dose on the day of colonoscopy vs split dose: OR, 4.04; 95% CI, 1.43-11.5), symptoms during bowel preparation (high symptom score: OR, 3.21; 95% CI, 1.15-8.95), and pain during the procedure (OR, 2.47; 95% CI, 1.40-4.35). Increasing number of working hours and less comfortable jobs were associated with absenteeism (P for trend =.06) and impairment of working performance (P for trend =.01) and GI symptoms both before and after colonoscopy. Conclusions: Occupational and individual characteristics of patients should be considered when scheduling colonoscopy because this procedure may impair work productivity in up to one-third of patients. Split-dose bowel preparation, performing a painless colonoscopy, and preventing the occurrence of GI symptoms may minimize the impact of colonoscopy on work productivity.