What is the mechanism of Sodium sulfate as a laxative?

An oral formulation containing Sodium sulfate having osmotic laxative activity. Following oral administration of Sodium sulfate laxative, this osmotic laxative promotes water retention in the intestines. This increases the water content of the faeces, thereby increasing peristalsis and facilitating the expulsion of the contents of the colon. This results in a complete cleansing of the colon. The osmotic activity of Polyethylene Glycol 3350, Sodium Sulphate, Sodium Chloride, Potassium Chloride, Sodium Ascorbate and Ascorbic Acid does not normally result in a net absorption or excretion of ions or water when taken with 1 litre of additional clear liquid.

References:

[1] Sodium Sulfate/Potassium Sulfate/Magnesium Sulfate-based Laxative[J]. Definitions, 2020. DOI:10.32388/wmhxho.