Vicki she can be intolerant to dairy and it will not show on an Ige test. So instead of an immune system reaction (allergy) it is a digestive system reaction (intestinal). If there are stomach cramps and blood in the stool it sounds to me like it is more of an intolerance than an allergy. My DS did also have skin reactions, which although is more commonly allergic response, is also an intolerance response.
When people talk of 'milk allergy' or 'dairy allergy' it is often just used as a catch all term, and does not always mean "allergy." My DS was intolerant, there was no immune system reaction, but his paed also used the term "allergy" rather than intolerance. He felt that people misunderstood the term intolerance and many parents felt that then what they needed to do was to "build up a tolerance" (and so fed them more milk to do so......) or that when they were in daycare or school, people did not take it seriously that the LO needed to abstain from dairy. But when you say "allergy" people get it, they understand it means "can not have under any circumstances" and so he personally just uses the word allergy instead. But in reality, it is often NOT an allergy.
What is your reason for needing to have a test done? Is there any way that you are she will benefit from having something recorded that she reacted (ie an insurance payment for HA formula or something?) If not then I would not even bother having any kind of test done - just keep her off of the dairy and every 10-12 months offer a milk challenge and see how she reacts. In England they won't test - there is no reason to. OK yes in some cases there is a need to, such as when the allergen or offending food is not known, but when you know the child reacts to dairy, keep them off....no test needed for what you already know to be true iyswim.