Daily consumption of sulfate- and magnesium-rich mineral water enhances bowel function in adults with chronic constipation: a randomized double-blind real-world trial.

INTRODUCTION

Functional constipation is one of the most common disorders of gut-brain interaction. Adequate hydration is recommended as first-line therapy, yet evidence regarding the efficacy of sulfate- and magnesium-rich mineral water remains limited. Therefore, this study investigated its efficacy and safety in a nationwide decentralized randomized controlled trial.

METHODS

In this randomized, double-blind, controlled parallel-group trial, adults with chronic constipation according to the Rome IV criteria consumed either 1 L/day of sulfate- and magnesium-rich mineral water (HSM) or a low-mineralized control water (LSM) for 3 weeks following a one-week run-in period. Participants maintained a total daily fluid intake of at least 1,5L/day. The primary outcome was the change in weekly bowel movement frequency after 3 weeks. Additional analyses were conducted after 2 weeks of intervention. Secondary outcomes included stool consistency, responder rates, time to treatment response, constipation-related symptoms (PAC-SYM), constipation-related quality of life (PAC-QoL), gastrointestinal transit time, laxative use, and safety.

RESULTS

After 2 weeks (additional analysis), bowel movement frequency increased significantly more in the HSM group than in the control group (mean change: 1.31 ± 3.24 vs. 0.34 ± 2.49 bowel movements/week; p = 0.043). This effect was more pronounced in participants with moderate-to-severe constipation (p = 0.022). No significant between-group difference was observed at the end of week 3 (p = 0.144). Time to treatment response was significantly shorter with HSM water than with control water (median 9 vs. 16 days; p = 0.042), accompanied by a higher responder rate in participants with moderate-to-severe constipation (p = 0.043). No significant between-group differences were observed for stool consistency, constipation symptoms, quality of life, or gastrointestinal transit time. Both interventions were well tolerated, and only mild transient adverse events were reported.

DISCUSSION: Daily consumption of 1 L of sulfate- and magnesium-rich mineral water, combined with adequate hydration, improved bowel movement frequency at week two and accelerated treatment response in adults with chronic constipation, whereas the between-group difference at the registered primary endpoint (week three) was not statistically significant. These findings suggest that sulfate- and magnesium-rich mineral water may serve as a safe, non-pharmacological dietary approach for the management of chronic constipation under real-world conditions.

CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/, DRKS00034871.