The impact of poor bowel preparation on colonoscopy: a prospective single centre study of 10,571 colonoscopies

Abstract

Objective: Colonoscopy is regarded as the most sensitive method of evaluating the colon. Inadequate preparation reduces sensitivity and has adverse implications for individual patients and the Heath Service.

Method: Data concerning the adequacy of bowel preparation and colonoscopy completion rates were prospectively collected on all colonoscopies performed in a single centre between January 1996 and January 2005. In addition, the strategy of further investigation in the event of incomplete examination was assessed.

Results: A total of 10 571 colonoscopies were assessed and poor bowel preparation was identified in 1788 of these cases (16.9%). The completion rate was 67.5% in those with satisfactory preparation. In patients with poor preparation, 36% of colonoscopies were complete. Incomplete examination was more likely with poor preparation [OR = 3.76 (95% CI, 3.38-4.18), P = 0.0005]. Poor preparation was more likely for inpatients [OR = 3.54 (95% CI 3.14-3.96), P = 0.0005]. Even with satisfactory preparation, inpatient completion rates were significantly less [OR = 1.78 (95% CI, 3.14-3.96), P = 0.0005). A further 542 diagnostic procedures were undertaken in the poor preparation group, an additional pound101 950 (euro149 459) in expenditure.

Conclusion: This study supports the view that inpatients fare badly. This is partly explained by higher rates of poor preparation; however, completion rates were reduced even with adequate preparation. Failed investigation and prolonged hospital stay increase cost. Colonoscopy completion rates need to be improved with particular attention to inpatients.