Introduction: The outcome of bowel preparation depends on several factors. One such factor is proper timing, especially the duration from completion of the preparation to colonoscopy.
This interval should not exceed 4 hours when using polyethylene glycol (PEG). It is unknown whether this recommendation is also valid for low-volume formulas.
This study aimed to determine the appropriate timing of bowel cleansing using such formulas. Methods: Subjects referred for a colonoscopy were prepared using PEG/ascorbic acid (MOV), picosulphate/magnesium citrate (PICO), or sulphate solution (EZI).
The quality, tolerability, length of the preparation (T-pripr), and interval from completion of the preparation to colonoscopy (T-vys) were assessed. Results: Preparation quality depended on both T-pripr and T-vys (p 9.0 vs. > 7.0 and > 6.5 hours, p = 0.01).
T-vys was also longest for PICO (<= 13.0 hours, p = 0.001). There was no difference between MOV and EZI (<= 10 and <= 11 hours).
Time factors did not affect preparation tolerability. Conclusion: The quality of bowel cleansing depends not only on the interval to colonoscopy but also on the length of the preparation.
Optimal time points are comparable for osmotically acting low-volume laxatives, but longer for PICO. Time factors do not affect preparation tolerability.