Jeremy,

I developed severe LI beginning last March for
unknown reasons.  Since then I've developed a pretty
good sense of what I can and cannot eat and what the
reaction will be.  Examples: If I have a handful of
chocolate chip cookies containing whey as a lesser
ingredient and no Lactaid pills, I will release small,
noxious bursts of odor within an hour or two but feel
otherwise fine.  A couple of slices of cheap pizza with a
few Lactaid Ultra pills will produce, at worst, the same
reaction.  The same goes for a bowl of frozen yoghurt
with no pills.  But last August I dared try a pasta
carbonara (like fettucine alfredo) with a few Lactaid
Ultras at a restaurant.  I ran to the bathroom with
severe diarrhea halfway through the meal.  The
diarrhea continued every so often for about the next 24
hours until all the lactose had been flushed from my
system (though I otherwise felt perfectly fine - no
cramps, nothing).  I had similar reactions to foods
containing large amounts of lactose before that event.
Since then I've avoided them like the plague.  But
recently I tried a couple slices of good quality pizza
with low fat mozzarella and thick bread from a
gourmet deli (with some Lactaid pills).  My stomach
started turning with the first bite.  The low fat cheese
has more lactose than the cheap stuff and the dough
must have had whey in it.

Good luck figuring things out.

Dave