It seems I was grossly mistaken about the formation of intestinal gas when drinking wine. A friend put me straight, though…
The sulfite (NOT sulfate) ions react with the hydrochloric acid in the stomach to form sulfurous acid:
SO3(-2) (aq)+ 2H3O(+1) (aq)<===> H2SO3(aq) + 2H2O(l)
Sulfurous acid is not nearly as stable as its cousin, sulfuric acid, and in a water solution is in equilibrium with sulfur dioxide and water:
2H2SO3 <===> 2SO2(g) + 2H2O(l)
Of course, as the SO2 escapes through the colon(to cause bloating and, later, flatulence) more sulfite reacts to form more SO2…For more bloating, and more flatulence.
(edited for stoichiometric consistency)