Introduction Inadequate bowel preparation for colonoscopy is associated with increased complication rates and a reduction in diagnostic yield. Low volume 2L polyethylene glycol and ascorbic acid (Moviprep, Norgine Pharmaceuticals) has been demonstrated to be non-inferior to other bowel cleansing agents but has greater patient tolerability (1). It is not known whether the addition of clear fluids to the standard regiment improves bowel cleansing with Moviprep.

Methods All adult patients attending for routine out-patient colonoscopy at two secondary care sites were randomised to receive either standard 2L Moviprep (regimen 1) or standard 2L Moviprep with an extra 1.5L of clear fluid (regimen 2). Segmental, and overall, bowel cleansing was assessed by the colonoscopist, blinded to the randomisation, using the validated Harefield Scale (HS). The HS is an inverted Ottawa scale scored from 4 (colon empty and clean) to 1 (large amounts of irremovable residual faeces) in six colonic segments.

Results 496 patients (252 females, mean age 59 years (range 22–90)) were included in an intention to treat analysis. The unadjusted completion rate was 95%. 246 patients were randomised to regimen 1 and 250 patients to regimen 2. Groups were similar in terms of demographics, indications for colonoscopy, presence of comorbidities and completion rates. Table 1 details the segmental, and overall, scoring between groups. Polyp detection rates were significantly higher in the group who took extra fluid (odds ratio 0.57, 95% confidence interval 0.34–0.89, p = 0.01).

Conclusion Increasing the volume of clear fluid intake with Moviprep improves cleansing in the distal colon and improves polyp detection rate. These data have important implications for clinical practise as upto 2/3rds of colorectal cancers arise in the left colon (2). Further research is now warranted to reproduce these findings in a larger cohort of patients.

Disclosure of Interest None Declared.

References

1. Marmo et al. Effective bowel cleansing before colonoscopy: a randomised study of split-dosage versus non-split dosage regimens of high-volume versus low-volume polyethylene glycol solutions, GIE 2010; 72(2):313–320.

2. McCallion et al. Flexible sigmoidoscopy and the changing distribution of colorectal cancer: implications for screening, Gut 2001; 48(4):522–5.