Yes, it has crossed my mind. I'm going to the doctor's this week and I will revisit this question. Thank you for bringing it up. It's interesting that the colonoscopy Dr. didn't bring this up. No one has. They were just focusing on it's efficacy. But I have read on this site there have been a couple of people that said "all of a sudden their laxatives stopped working". That terrifies me. I've had difficulty all my life and it's only been one year since I contracted C-diff from an anti-biotic and it's taken this full year to recover. I still have to rely on the Prunelax and Bisacodyl to eliminate and that is concerning. Otherwise I become constipated as I have all my life. I can go on my own, but it becomes a problem. I've ALWAYS been that way. I believe it's because I have such a long transit time due to the long intestine I have for a person my size, the "tortuous intestine". So truthfully, this past year, finally finding Prunelax, is the first time in my life I've been able to eliminate "normally" and I feel so much better. I thought because Senna was a natural product I might not have to worry about dependence. But I will discuss this more with my doctors. I don't want another problem! I'll keep you posted. Thank you! Jacque