After viewing reader comments on your web site, I tried magnesium oxide to relieve IBS with constipation. My doctor had prescribed Zelnorm twice a day, and I had used it for three years. It worked quite well, but I was having to live my life around scheduling my medication and meals so the Zelnorm would be effective. If I didn't allow one hour after taking it before I ate a meal, the constipation along with bloating and nausea would return. I just couldn't see living the rest of my life like that. Not to mention the expense of taking a one-of-a-kind drug. Then while researching IBS with constipation, I noticed your web site. I began taking 250 mg magnesium oxide on an empty stomach first thing when I awaken each morning. By the time I'm ready for breakfast, it has had its desired effect. Thanks so much! I am so appreciative of the help I found.