Can I take magnesium citrate ontop of my miralax (polyethylene glycol) for bowel prep? 1 gallon of miralax (polyethylene glycol) is too much, can I only drink half a gallon?

Just mag citrate. You can have just magnesium citrate. Why are you having bowel prep. Discuss with your physician if mag citrate is a substitute that is satisfactory alternative. Tell him miralax (polyethylene glycol) volume is too much. However though discomfort it is do-able for most people .