The citrate salt of the element magnesium with cathartic activity. The cathartic action of magnesium cations appears to result, in part, from osmotically mediated water retention, which subsequently stimulates peristalsis. In addition, magnesium ions may also stimulate the activity of nitric oxide (NO) synthase and increase the biosynthesis of the phospholipid proinflammatory mediator platelet activating factor (PAF) in the gut. NO may stimulate intestinal secretion via prostglandin- and cyclic GMP-dependent mechanisms while PAF produces significant stimulation of colonic secretion and gastrointestinal motility.