Comparison of sennoside A + B and sodium picosulfate-based regimens for bowel preparation: a prospective randomized trial.

aimAdequate bowel preparation is essential for high-quality colonoscopy and directly affects key quality indicators such as adenoma detection and cecal intubation. Although low-volume, nonpolyethylene glycol (PEG) regimens are widely used in clinical practice, real-world comparative data between stimulant-based preparations and sodium picosulfate-based combinations remain limited. This study aimed to compare the effectiveness and tolerability of sennoside A + B versus sodium picosulfate/magnesium oxide/citric acid (PM/Ca) using the Boston Bowel Preparation Scale (BBPS).

methodsThis prospective, randomized, observer-blinded trial included adults aged 18-80 years undergoing elective outpatient colonoscopy. Participants were randomized 1:1 to receive either sennoside A + B oral solution (split-dose: 250 mL at 21:00 and 250 mL at 23:00) or PM/Ca (two sachets at 19:00 and 21:00), both administered with a low-residue diet and written instructions; rectal enemas were applied as part of the institutional protocol. Bowel cleanliness was assessed using BBPS. Adequate preparation was defined as BBPS > 6. Multivariable logistic regression was performed to identify independent predictors of adequate preparation.

resultsA total of 705 patients were included in the primary analysis cohort (341 sennoside A + B; 364 PM/Ca). Adequate bowel preparation (BBPS > 6) was achieved more frequently in the sennoside A + B group than in the PM/Ca group (70.1% versus 56.3; p < 0.001), and the mean BBPS score was higher (6.64 ± 1.78 versus 5.93 ± 1.92; p < 0.001). Polyp detection rates were similar between groups (21.4% versus 26.6; p = 0.138). In multivariable analysis, higher education (OR 1.38; 95% CI 1.06-1.81; p = 0.016) and sennoside A + B (OR 1.77; 95% CI 1.29-2.43; p < 0.001) were independent predictors of adequate preparation, whereas age, BMI, sex, diabetes mellitus, and constipation were not. Preparation intolerance was more frequent in the sennoside A + B group (7.0% versus 0.7%; p < 0.001; tolerance analysis n = 824). Failure to reach the cecum did not differ significantly between regimens (9.3% versus 12.3%; p = 0.216; analyzed in the entire study population n = 791).

conclusionsIn routine clinical practice, sennoside A + B provided higher cleansing efficacy than PM/Ca as reflected by higher BBPS scores and a greater probability of achieving adequate bowel preparation. However, PM/Ca demonstrated a more favorable tolerability profile. Bowel preparation selection should balance efficacy and tolerability while considering patient-related factors such as educational level.

trial registrationClinicalTrials.gov, NCT06580366.