I think I was on it for about 3 weeks to one month before the rash started, Jean. Then, I broke out in these ugly red, raised pimple-like bumps. It started out very little, on my legs. Then, it increasingly became worse, and covered most of my body. My doctor just had me lower the dose, but continue to use it. It went away in about 7 to 10 days on it's own.
Just let your doctor know if you start breaking out in a rash, even if it's a little bit. I hope your stomach feels better soon.