Low-dose of magnesium sulfate solution was not inferior to standard regime of polyethylene glycol for bowel preparation in elderly patients: a randomized, controlled study

Background: Large polyethylene glycol (PEG) is a standard regimen for bowel preparation. However, elderly patients suffered from adverse events. This study was to compare the efficacy and safety of oral magnesium sulfate solution (MSS) vs standard PEG in elderly patients undergoing colonoscopy.

Methods: Elderly patients aged 60-90 years, from two endoscopic centers, were enrolled in China. Patients were randomized to take a low dose of MSS or a standard PEG regime in a split-dose regime. The primary endpoint was the proportion of patients with adequate bowel preparation, which was defined as the total Boston Bowel Preparation Scale (BBPS) ≥6 and each segmental BBPS was ≥2. Secondary outcomes included adenoma detection rate (ADR), safety, adverse events, cecal intubation rate, willingness to repeat BP, and so on.

Results: 1174 elderly patients were randomly allocated to the MSS group (n = 588) or the standard group (n = 586). Adequate BP was achieved in 94.0% of patients in the MSS group and 92.5% in the control (p = .287). ADR was also comparable between the two groups (43.0% and 39.9%, p = .282). Compared with the standard group, MSS group reported less abdominal discomfort (1.7% vs 6.0%), less nausea (13.6% vs 21.0%) and vomiting (1.2% vs 4.2%). The change in serum potassium levels after preparation in the standard group was significantly lower than that in the MSS group (-0.19 ± 0.08 vs -0.41 ± 0.11, p = .037).

Conclusions: Low dose of MSS was not inferior to the standard PEG regime in terms of bowel preparation quality for elderly patients. Low-dose MSS offered fewer adverse events and better tolerability. It is a preferable choice for the elderly to undergo bowel preparation for colonoscopy.

Clinical trial registration number: NCT04948567.