Conventional regimen versus split-dose regimen in bowel preparation: Results of a randomized controlled trial

Introduction-Aim: Good bowel preparation is essential for colonoscopies. This study aimed to compare the quality of bowel preparation between the split-dose regimen (SD), recommended by European endoscopy societies, and the conventional regimen (CR) in Tunisia, where SD is not routinely adopted, and to identify factors leading to poor preparation in both groups.

We performed a randomized controlled trial, spread over four months (January-April 2019). Patients were randomly assigned to two groups at a 1:1 ratio: SD or CR.

One hundred and thirty-three patients were included: 65 in the SD group and 68 in the CR group. SD showed better bowel cleansing than CR by comparing the mean Boston score in the two groups (6.05 versus 4.75,  p =<0.001). Tolerance of the preparations was comparable between the groups. Factors associated with poor preparation in the SD group were constipation (p=0.04) colonoscopy indication (screening) (p=0, 01) and public transport (p=0.001). In multivariate analysis, constipation and public transport were independent factors in poor preparation with a relative risk of 4.9 and 26 respectively. For the CR group, age <65 years (p=0.022), low level of education (p=0.03) and unemployment (p=0.015) were predictive factors for poor preparation. In multivariate analysis the low level of education was an independent risk factor for poor preparation with a relative risk of 20.

Our study showed that SD provides better bowel preparation than CR without altering the tolerance. In addition, factors predictive of poor preparation in the SD group were modifiable, unlike those of CR.