[Effective bowel preparation before coloscopy - low-volume PEG in the divided dose regimen]

The good and safe bowel cleansing is key to the success of coloscopy. The standard preparation involves 4 l polyethylene glycol (PEG). Now the combination of PEG and ascorbic acid (PEGA) of half the volume is available. Besides the type of product also the time factors which are not clarified, play a role during the bowel preparation. The aim of the study was to compare the efficiency and tolerance of both the agents and evaluate the effect of the time regimen of preparation.

380 individuals were included in the evaluation in 4 cohorts which used 4 l PEG (Fortrans) in a single dose or split into 3 + 1 l and PEG + ascorbic acid (Moviprep) split into 1 + 1 l or 2 l one day before examination.

There was no difference between the agents as to the quality of bowel preparation, when they were used in the same regimen. The bowel cleansing was better in both cases in the divided dose regimen (p < 0.001), and it was inversely proportional to the length of preparation (p = 0.003) and directly proportional to the length of time between the end of preparation and coloscopy (p < 0.001). PEGA was better tolerated (p < 0.028), regardless of the preparation regimen.

PEG and PEGA are similarly efficient in the bowel preparation before coloscopy provided they are used in a similar regimen. The best results are reached when the preparation is divided into 2 days. PEGA is better tolerated than PEG, regardless of the used regimen. The quality of bowel cleansing is affected by the length of preparation (optimally up to 12 hours) and the time elapsed from the preparation until examination (up to 8 hours).