It makes sense that those with sensitive stomachs would have more sensitivity to high lateral root as opposed to low. They could just drink less to get the same effects and it would last longer. Are the compositions which make up the lateral roots virtually the same in profile just much more potent?
They could drink a bit less, but the point is that lateral roots tend to be generally more bitter and many people feel nauseous the moment they feel the bitterness. I guess a higher water to root ratio could mitigate this a little bit, but I am not 100% sure.
To be clear: I have never experienced any kind of unusual stomach upsets (naturally no kava in the world is 100% pleasant for the stomach) or negative side effects from drinking ANY of the
@Gourmet Hawaiian Kava 's products. I have tried the new, extra potent instant and I find it not only very powerful, but also velvet-smooth and easy to drink. I had some of the new micronized and it was just perfect.
Note that I have had bad experiences with other kavas from other vendors. One strain nearly made me vomit and another one gave me a terrible diarrhoea

. Since then I've mainly used Chris' products and I haven't had any problems at all. I think this is because of two things: 1) Chris' kavas are 100% pure, well-processed, well-packaged and reliable; 2) Chris' kavas are generally "heady" and most people find headier kavas to be more gentle on the stomach.
However, I do know that there are some people that can get the shits from just about any type of kava regardless of its chemotype and purity. These people might perhaps appreciate a more gentle "stump root only" blend..