P:, it would appear the original poster is looking for a simple chemical way to alter a fundamental property of ingested sorbitol -- large amounts eaten absorb water from the bloodstream into the GI tract, and since sorbitol is non-nutritive, the sorbital -water persists, all the way to, well, the end.
rolls:, most likely, there is no simple reaction to alter this phenomena. I suppose the preparation to be injested could be formulated without sorbitol.