Could a UTI be a symptom of some bigger infection/disease?

Some people are just prone, but I am not aware of a UTI being the result of another ailment, other than dehydration. I have heard that some of the newer white teas, green teas, fancy teas, seem to not agree with some folks' kidneys and bladders. Could it be ovaries or ligaments? Now dont laugh at this, but could you be lactose intolerant? this happened to a friend of mine and she had every doc in the world in there giving her every diagnosis in the world. Turns out she became lactose intolerant in her late 30's. The pain was awful and the docs were clueless. that was 20 years ago.