I too had  an exclusively breastfed baby that had terrible gas and
constipation from birth. I didn't realize until he was a older toddler and
drinking a lot of cows milk that he was dairy sensitive.  I now realize that
his constipation and gas as a baby was from the dairy products that I ingested
while nursing him.  I was able to prevent this in my 3 subsequent babies by
limiting my intake of dairy products.  My 4th baby was so sensitive that even
an occasional ice cream cone was enough to provoke a reaction.  The
BAB(Breastfeeding Answer Book) states that "one study found that mothers with
colicky babies had higher levels of cow's milk protein in their milk than
mothers whose babies were not colicky(Clyne and Kulczyki 1991). In another
study, 35 out of 36 mothers of colicky babies reported a decrease in their
babies' fussiness when they eliminated milk and milk products from their
diets(Jakobsson & Linberg 1983)  It may take ten days to two weeks to
eliminate cow's milk and milk products from her diet, encourage her to allow
the full two weeks before gauging the results. If there is a family history of
allergies, the baby is more likely to be sensitive to a food in his mother's
diet."   As a LLL Leader, I have witnessed dramatic results in many cases of
colicky or fussy babies when dairy products were removed from the mother's
diet. The thing that I caution mothers in removing dairy is to really check
labels because many prepared food items include dairy in them. Some mothers
think that dairy just means milk, not realizing that dairy includes cream,
butter ,cheese and ice cream. Some mothers find that yogurt will not bother
their babies because it is a cultured dairy product but in the beginning it is
wise to eliminate all dairy products.  Mothers may try dairy substitutes made
with soy, but are wise to watch babies for sensitivities to soy as (I have
seen various figures) many children that are sensitive to dairy are also
sensitive to soy as well.( This is the largest argument against giving babies
ABM)  Dairy substitues made of rice are very tasty and are sweeter tasting
than soy. Available in health food stores and some grocery stores rice
bevrages are marketed under such names as "Rice Dream". They come both
unfortified and fortified with added vitamins and calcium. The bonus to rice
milk is that it can be stored at room temperature until opened, thus allowing
one to stock up on it without spoiling. It is not a substitute for breast milk
until the baby is over 1 year of age.(I would recommend a mother discussing
this over with her baby's Dr. before using it)  My children love rice milk, it
even comes in handy juice box size with straw!   There are even ice creams
made of rice milk that are delicious!   If dairy is not the culprit with this
mother's baby, she should eliminate other common foods from her diet, such as
citrus, caffeine, and cigarettes . Anything in the diet can be a problem
however and I have worked with mothers that had infants that reacted to things
such as carrots, teas, tomatoes, chocolate etc.  Some vitamins supplements and
herbal supplements are big offenders too. Many mothers think that because
something is"natural" that it is safe. I myself am highly allergic to
chamomile, and ingesting a tea that has even a little chamomile is enough to
bring a violent migraine headache on. Mothers need to watch for multiple
sensitivities in their children too especially if  they have a family history
of food allergies. My 3rd baby was highly sensitive to dairy, soy and citrus
as a baby. This eliminated a lot of things from my diet!  She is now going on
4, and she is able to have small amounts of  these foods with no problem.
Many times a baby with a food sensitivity will show multiple symptoms of
allergy.  Other symptoms of a food allergy or sensitivity can be diahrrea,
rash, hives, frequent diaper rash, a red ring around the anus, a frequently
runny nose that is CLEAR, frequent drooling and puffiness under the eyes.
Different children in the same family with a sensitivity to the same food item
may exhibit different symptoms.  I find that in the case of dairy sensitivity,
that the mother will commonly state that either she or the baby's father or
other close relative is lactose intolerant.  I'm sorry that this is so long,
but I have 4 kids that are dairy sensitive and  have various allergies to
other food items, which has made it very hard to cook for all of them at
times!  There is really no foolproof way to test, trial and error and
elimination diets work the best.  Good luck!  Lisa Papas LLLL