I have definately been having success with magnesium, but I do find I have trouble finding the exact amount to take.If I don't take enough I get backed up after about a week, but if I take too much I get nausea. And 'too much' or 'not enough' seems on how full or empty my system is. Somedays I can take 500 and have no nausea, but other days 200 can give me nausea! Other times I get on a perfect cycle where it works for a long time, hence the success of the magnesium, but once it gets screwed up - usually by my period, then I have trouble getting back on track.I like taking it before bed, because that way it works right away when I wake up - and I only go in the AM.Is it just that I have to take it with food? Any other suggestions?Thanks, LindaP.S. For all those who where waiting for Zelnorm, I'm sorry to hear it wasn't approved.