Without knowing what vaccines she received it is hard to say, but there are two vaccines which cause sever problems in some kids. MMR and DPT. You will never get a doctor to admit that vaccines are the problem. I was in the hospital with an 9 month old baby who had her vaccinest and within 24 hours started to convulse. While she is was in the hospital room with us, I could see she was having petite mall seizures, and both parents and I thought that it was the vaccine DPT (specifically the Pertussis part thereof), but the doctors wouldn't even entertain that possiblity. I can't remember which, (I am pretty sure it is DPT) they have found in england causes severe problems in the colon, causing toxins to be released into the blood. I don't know what state you are in, but in some states you can delay the vaccines or request that only one vaccine be given at a time, aka. just measels, not MMR, or just Tetnus, not DPT. That way their systtem is not overwhelmed by all of the vaccines, and the toxins that are used to bind the vaccines together. If it stops, I think you would be okay, but I do not think it is a mild allergy. My brother had one, and he never had blood in his stool, just runny, runny poop. And here is a tidbit for you, I know this is going to upset all who read it, but I will fill you in. None of us have the enzymes to digest cow's milk. In fact, we loose the enzyems to digest breast milk at a certain age. That is why so many people are "lactose intolerant". News flash, we all are.
Good luck, and consider seperating or delaying the vaccines until she is older. I did that with my daughter and son until we moved to New york, and they do not allow that, so they had to be all caught up very quickly. If you are in a state that allows a philosphical waiver, you can have the vaccines given whenever YOU are comfortable. Also, get the list of ingredients from the vaccines (dr has to provide) and schedule an appointment with a pediatric allergist. They may help you as they may prescribe that only one vaccine be give at a time so they can determine if they are allergic to any of the binders and fillers in the vaccine. I know there are lots of pressure to do everything on the state mandated schedule. But stand your ground, and do as much research and get an allergist involved. You will feel better and so will your daughter.
L.