First of all, I am not a Doctor. I will attempt to answer some, but not all, of
your questions. My understanding, from multi-year personal experience goes like
this:
    * LI is lactose intolerance and is exactly that. Your body doesn't produce
    enough of one type of enzyme and the body has difficulty processing the
    untreated sugars. This situation results in bloating, diarrhea, etc. I have
    been LI for roughly 18 years.
    * An allergy, on the other hand can range from a severe reaction such as
    anaphylaxis to feeling ill. I have suffered from a relatively mild allergy
    for roughly 5-6 years. The problem went away when I stopped ingesting all
    dairy exactly 3 years ago.
    * When you mention that some things bother you but others don't. There
is an
    explanation. Butter doesn't have a great deal of lactose in it and if you
    eat it with other foods, doesn't affect you. I experienced a similar thing.
    But try a glass of regular milk on an empty stomach and see what happens! I
    found out by process of elimination that I could eat a dairy protein called
    casein, whereas anything with whey was very bad. However, most people,
    according to what I have read, react to casein.
    * An Internist (Doctor) I went to see said I could also be intolerant to
    chocolate. Every once in a while I react to something in chocolate but not
    cocoa. Chocolate chips which were certified Kosher Pareve (dairy free)
    caused me a problem. It's not clear to me what is happening. I'm offering
    it as a comment when you say you react to chocolate.
    * To complicate matters, most LI symptoms seem to be very close to
Irritable
    Bowel Syndrome. So when I eat fruit or drink fruit juice on some occasions,
    I get the same intestinal problems as I do for LI. As an aside, some OJs
    cause a reaction, others don't. Go figure.
    * Lastly, no one in medicine can properly diagnose your particular
    situation. Most Doctors just don't have the knowledge or time to diagnose
    accurately. On an airplane trip, a passenger seated next to me explained he
    had IBS. When he said what the symptoms were, I said he should check
    whether he was LI. The symptoms he reported were classic LI. The point is
    -- you have to do some empirical testing. That is very complex unless you
    absolutely know what you've eaten. I found it difficult because LI or IBS
    reactions are with 6 hours or so. But dairy allergy reactions for me start
    at about 36 hours and run for up to 72 hours. Try to imagine what foods
    you've eaten and, whether you prepared them or not, and what your reaction
    was, and what the time frame was. That's too many variables for most
    analytic exercises. But it can be done. It just takes a while. You could
    try an elimination diet but I didn't have the fortitude to try it. That is
    usually reserved, I suspect, for people with more serious allergies than I
    do
I hope this helps. Please remember that I  have never been properly diagnosed
as having a dairy allergy (but was for LI). But my life has dramatically
improved since I stopped all dairy 3 years ago. And, by the way, most
margarines have dairy in them. Check the container for "whey". It's usually
1.4-1.8%

Good luck.

Don M

At 10:28 PM 00/01/08 -0800, you wrote:
>
>I've been reading messages now for a few months and have learned a lot
>for which I'm grateful.  However, for every question that is answered,
>two are left unanswered!