Safety and efficacy of aspartame-based liquid versus sucrose-based liquids used for dilution in oral sodium phosphate solutions for colonoscopy preparations.

The aim of this study was to investigate whether an oral sodium phosphate solution (OSPS) mixed with aspartame-based clear liquids as the diluent would yield improved colon cleansing results compared to an OSPS mixed with sucrose-based liquids as the diluent. Fifty-one patients undergoing colonoscopy were prospectively randomized into two groups to receive different OSPS colonoscopy preparations, with sucrose-based or aspartame-based liquids used as diluents. The primary end point was the quality of the colonoscopy preparation and secondary end points were serum electrolytes before and after preparations. No significant difference in colonoscopy preparation quality was seen between the two OSPS diluent groups (Mantel-Haenzel chi (2) = 0.795, P = 0.484). There were no significant differences in mean electrolyte shifts of sodium, potassium, blood urea nitrogen (BUN), creatinine (Cr), or BUN/Cr ratios between the two groups. There was a statistically significant increase in serum phosphorous in the aspartame-based group compared to the sucrose-based diluent group (P = 0.021). In conclusion, there was no clinically detectable difference in colonoscopy preparation quality between the two OSPS diluent groups. This study suggests that passive fluid transport by aquaporins may well be the major mediator of fluid shifts in the study subjects. This result suggests the potential importance of aquaporins and minimizes the importance of sodium glucose cotransporter SGLT1 in fluid and electrolyte transport in the human gastrointestinal tract. Aspartame or its constituent amino acids may enhance phosphate absorption across the human small intestine.