The renal safety of bowel preparations for colonoscopy: A comparative study of oral sodium phosphate solution and polyethylene glycol

Background: Rare cases of nephrotoxicity have been reported with oral sodium phosphate solution (OSPS). Aim: To evaluate whether OSPS is associated with changes in renal function. Methods: A chart review performed on 311 patients who had colonoscopy at the James J. Peters VA Medical Centre prepared with either OSPS (n = 157) or polyethylene glycol (PEG) (n = 154). Patients had a baseline serum creatinine ≤1.5 mg/dL. Effect of bowel preparation on the renal function was evaluated by measuring the absolute change in levels of serum creatinine and the proportion of patients who developed a 50% or more increase above their baseline serum creatinine value. Results: Oral sodium phosphate solution resulted in a slight increase in serum creatinine from 1.0 ± 0.02 to 1.1 ± 0.02 mg/dL (P = 0.07) and PEG resulted in a small decrease in serum creatinine from 1.1 ± 0.02 to 1.0 ± 0.03 mg/dL (P = 0.03). The absolute change in serum creatinine was slightly higher with OSPS than with PEG (0.04 ± 0.02 vs. -0.05 ± 0.02 mg/dL; P = 0.005). However, the proportion of patients who had a ≥50% increase above their baseline creatinine was similar (OSPS vs. PEG, 5% vs. 3%, P = 0.77). Conclusions: Oral sodium phosphate solution was associated with a slight increase in serum creatinine, which was not clinically significant. Renal toxicity from OSPS appears to be minimal when used in patients with serum creatinine value <1.5 mg/dL.