When diagnosed as MSPI you must avoid anything with milk or soy in them.  This is sometimes easier said than done.  You will have to become good at reading labels.  The first time I went shopping I spent nearly 2 hours in the grocery store and left with two products!!  It does get easier with
time and experience.  The organic isle in your local grocery store is a good place along with any local health food stores you may have.

Soy                                                                       Milk
soy or soya anything                                    casein/caseinate
tofu                                                                       hydrolyzed casein
miso                                                                      hydrolyzed milk protein
tempeh                                                                lactate/lactose
edamame                                                            lactoferrin/lactoglobulin
natto                                                                     modified milk ingredients
yuba                                                                      whey
okara/akara                                                               
rennet
TSF-textured soy flour
TSP-textured soy protein
TVP-textured vegetable protein
tamari
shoyo sauce

Also avoid anything with the following in the ingredient list:  lecithin;
vegetable, plant, or bean (such as broths, gums and starches); guar;
xanthan or zanthan; vitamin E or tocoopherol; MSG (monosodium glutamate);
natural or artifical flavor; glycerine.

Beware also of vegetable oil in ingredient lists.  Always assume this is soy based unless it specifically says for example: vegetable oil (canola
oil and/or corn oil).  This one would NOT have soy in it.  However one that says vegetable oil (canola oil and/or soybean oil) does.  And always
assume that one that just lists vegetable oil IS soy based.

Be sure also to avoid foods that say that they are processed on the same equipment as products containing milk or soy ingredients.  This can result
in cross-contamination and sensitivity to the product even though it doesn’t contain milk or soy itself.

The other option is to contact the manufacturer and ask if soy is in the product.  Mention the actual ingredient such as “natural flavoring” and
ask if it is made with soy as a carrier protein or “vegetable oil” and ask which oil they are referring to. Never assume that just because it doesn’t
specifically say soy that it isn’t made of soy.