Quote Originally Posted by SadieKate View Post
Since I recently had this discussion, I just copied this verbatim from an old email of mine:

Speaking of kidneys, I tried to google sorbitol-free hydration tables and found a post on RW's forum from an internal med doc responding to someone complaining about GI issues with Nuun. He stated that Nuun contains 3 laxatives: magnesium sulfate (epsom salts), sorbitol, and polyethylene glycol (Merilax). He also said he was surprised that most people don't have GI issues from it.

I cannot tolerate sorbitol so the only tablet I have tried is Nathan. When I only have an hydration bladder to carry liquid, I use Elete drops and a Nathan tablet for flavoring. Elete seems to have the best balance for both me and my hubby. When I have a water bottle and need to be taking in calories also, I'll use Cytomax and bump up the electrolytes with Elete.
I can tolerate Nuun, but only maybe a bottle/day. If I'm doing a long ride with several bottles of fluids I avoid it...because of the sugar alcohol (sorbitol) induced toots. I don't need to be jet-propelled on my bike. Nuun says that the amount in their tablets isn't enough to cause gastric issues, but I call foul on that claim. I'd rather just pop Endurolytes or other electrolyte capsules if I want electrolytes without flavor or calories.