Oregondaisy 2,021 Posted June 2, 2015 I worry about my kidneys because my labs always come back with the kidney function level being high. That's why I won't use Miralax anymore. My doctor said it's only meant to be used for 2 weeks and after that, it's hard on the kidneys because it draws Water out and into the stool. I do use Magnesium sometimes, but again, it's another strain on the kidneys. I've found the best thing with no side effects is Mtamucil. I mix it with crystal light and drink it fast. It doesn't taste bad . It just gets thick if you don't drink it fast. It's just adding Fiber which our bodies need. Share this post Link to post Share on other sites