I have been on Levsin for over a year now, most of the time it works if I take one in the morning and one at night. I don't care to much for the side affects, they really have gotten bad lately. Dry mouth, anxiety attacks, sensitive to sunlight and heat. I have had IBS for 10years now, since I had my gallbladder out. I am going to try the Caltrate, I discussed it with my Doctor he said Calcium is good for you anyway, can't hurt you, he also suggested Fibracom or Metamusil, but I thought Fiber made you go. I am IBS with "D" and pain! Best of luck with Levsin but make sure you take it regularly, don't skip or wait.