Magnesium oxide has long been used as a laxative, particularly in East Asia, based on empirical knowledge and traditional practice. Its use has recently gained renewed interest due to its low cost, ease of administration, and overall safety profile.
Clinical and observational studies indicate that magnesium oxide effectively improves stool frequency and consistency in patients with chronic or functional constipation. In pediatric populations, treatment with magnesium oxide increased defecation frequency, softened stools, and reduced the need for enemas compared with placebo.
Appropriate dosing is important to minimize risks, particularly hypermagnesemia, which is more likely in elderly patients or those with impaired kidney function. Recommendations suggest starting with a lower dose of around 1 g per day in divided doses and adjusting according to symptoms and laboratory monitoring when necessary.
Magnesium oxide can also interact with other medications, including antibiotics, bisphosphonates, and iron supplements, potentially affecting their absorption.
Overall, magnesium oxide is considered a viable, convenient, and low-cost option for treating constipation. However, careful attention to dose, renal function, and potential drug interactions is necessary, and further long-term studies are required to compare its efficacy with newer laxatives.
Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7911806/