If you even read a bottle of metamucil or citrucel it also says, don't use long term unless directed by doctor. I think it's just something they have to say. My doctor said that miralax is the safest type of laxative and that you can return to "normal" after going off of it. The electrolyte imbalance is if you are not getting enough water and fluids in your system when you take it...as with anything else... Don't read into it to much. My doctor tells me to stay away from things I read on the internet. It seems that Miralax is the most popular amongst doctors, so I trust it. As for me, being ED past and now having the enlarged colon, my doctor told me that I'll have to be on something forever..so, I don't even care anymore as long as I can go...but I know it's not comforting knowing that. If you went off the miralax, you could return to normal..if you were taking like exlax everyday, something harsh, that would be a different story. Talk to your doctor and I'm sure he'll tell you similar.