Rescue bowel preparation: same day 2 L polyethylene glycol addition, not superior to bisacodyl addition 7 days later

Abstract

Background: The optimal colon-cleansing method after failure of bowel preparation (BP) for colonoscopy has not been established.

Aims: We aimed to compare BP rescue methods after failed initial BP and to identify risk factors for rescue BP failure.

Methods: Eighty-five patients with BP failure after 4 L polyethylene glycol (PEG) ingestion were prospectively enrolled from March 2008 to March 2012. A second colonoscopy was performed either on the same day after ingestion of another 2 L PEG (group A) or 1 week later after ingestion of 4 L PEG plus 20 mg oral bisacodyl (group B). Differences between groups in terms of BP quality and risk factors for a poor BP on the second colonoscopy were investigated.

Results: Median patient age was 59 years, 45 were male (52.9 %), and 17 (20 %) had poor BP on the second colonoscopy. For group B, the multivariable-adjusted odds ratio (OR) for poor BP on the second colonoscopy relative to group A was 0.68 (95 % confidence interval [CI], 0.16-2.95). Adequately ingested PEG during the initial colonoscopy was associated with poor BP on the second colonoscopy (OR 4.05; 95 % CI 1.04-15.75). The two groups had similar patient discomfort rates during the second BP.

Conclusions: The two groups did not differ in rescue BP failure rate. Initial BP failure after adequate consumption of 4 L PEG may be a risk factor for rescue BP failure. A stricter BP regimen should be considered for these patients.