About magnesium citrateosmotic laxativemechanism of action of magnesium citratemagnesium citrate works by attracting water through the tissues by a process known as osmosis. once in the intestine, it can attract enough water into the intestine to induce defecation. the additional water helps to create more feces, which naturally stimulates bowel motility. this means it can also be used to treat rectal and colon problems. magnesium citrate functions best on an empty stomach.indications for magnesium citrate1.to clean stool from the intestines before surgery or certain bowel procedures (e.g., colonoscopy, radiography) 2.dietary supplement 3.laxative 4.antacid