Split-dose sodium picosulfate/magnesium citrate (SPMC) and polyethylene glycol (PEG) are safe and adequate at-home bowel preparation agents for outpatient colonoscopies, but patient satisfaction, ease of use, and adherence were found to be higher with SPMC. These findings, from a systematic review of 8 randomized controlled trials, were published in Clinical and Experimental Gastroenterology.

An international team of researchers searched publication databases through February 2020 for studies of split-dose preparations of SPMC and PEG bowel evacuation agents. The final analysis included 8 articles published in 2013 or later with sample sizes between 141 and 973 patients. The studies included 4 prospective, randomized, single-center trials; 3 prospective, randomized, multicenter studies; and 1 noninferiority, randomized, single-center investigation. The trials were conducted globally and scored patients using the Ottawa Bowel Preparation Scale (OBPS; n=4), Aronchick Score (n=3), or Boston Bowel Prep Score (BBPS; n=3).

SPMC was found to better prepare patients for colonoscopy in 1 study from Rostom et al (SPMC mean OBPS, 4.14±2.64 vs PEG OBPS, 5.11±3.44; P =.019). In the remaining studies, similar outcomes were seen with SPMC and PEG preparations. For example, a study assessing patients with OBPS reported scores of 1.55±0.66 for SPMC and 1.74±0.88 for PEG (P =.08). Another study that used BBPS observed scores of 6 or above among 82% of SPMC and 80% of PEG recipients (P =.718).

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In general, split-dose approaches were superior to single preparations regardless of the solution type (SPMC Aronchick, 84.3% vs 60.2% and PEG Aronchick, 90.1% vs 68.8%, respectively; P <.006). Further, a 1-day split dose was inferior compared with a 2-day split dose (SPMC mean OBPS, 3.68±2.82 vs SPMC mean OBPS, 5.69±3.06; P <.001). Compared with a split dose administered across 1 day, 2-day split dosing was also superior in right colon cleanliness score (right bowel, OBPS 1.27±0.11 vs 2.10±.0.12; P <.001). Additionally, patients given a split regimen were more likely to present during colonoscopy with satisfactory cleanliness than those who used a same-day method (odds ratio [OR], 3.39; 95% CI, 1.1-10.4; P =.03).

A study reported SPMC as the best-tolerated (P <.006) and PEG as the worst-tolerated (P <.001) preparation; this finding was generally consistent across the investigations. Another study found that 93.6% of SPMC recipients would repeat colonoscopy preparation using that method compared with 59.7% who were assigned to PEG.

SPMC was observed to be more palatable (1[excellent]-5[bad] scale, 2.39±0.73) than PEG (3.06±0.93; P <.001). In per-protocol analysis, SPMC was found to be palatable (P <.001). Patients in this analysis also reported satisfaction with the preparation method (P =.032) and said they were able to comply with SPMC (P <.001). Ease of use was reported to be significantly greater among patients assigned SPMC (BBPS, 7.62±1.95) compared to PEG (BBPS, 5.92±2.35; P <.001).

This study was limited by reviewing analyses that included differing medication mixtures (eg, polyethylene glycol, ascorbic acid, and bisacodyl) and differing doses (eg, 2-L and 4-L doses).

The review authors concluded that split-dose SPMC and PEG were similarly effective bowel preparation agents prior to outpatient colonoscopy but noted that “split-dose SPMC may be associated with improved patient tolerance, adherence rates, and less side effects” than PEG.

Disclosure: An author declared affiliations with industry. Please refer to the original article for a full list of disclosures.


de Miranda Neto AA, de Moura DTH, Hathorn KE, Tustumi F, de Moura EGH, Ribeiro IB. Efficacy and patient tolerability of split-dose sodium picosulfate/magnesium citrate (SPMC) oral solution compared to the polyethylene glycol (PEG) solution for bowel preparation in outpatient colonoscopy: an evidence-based review. Clin Exp Gastroenterol. 2020;13:449-457. doi:10.2147/CEG.S237649