Hi Erin,
As always, you ask great questions. Often, I only think of a Blood stasis formula once the Damp formulas fail. That is, unless the physical appearance of the bladder during surgery or ultrasound clearly demonstrates stagnant circulation. Sometimes, too, the pulse will tell you. It'll start to feel weaker and more choppy; that is, the pulse feels weaker and less consistent from one beat to another. Another change could be the passage of clots or tissue fragments. Pain is common in all Blood and Damp Heat cases, so it doesn't necessarily help us.
Very, very chronic cases probably have a good chance of having a Stasis element, making time itself a potential indicator. The exception is recurrent infections that resolve between bouts. These could still be Damp Heat every time they crop up. So that does throw a wrench into the works regarding prescribing on the basis of chronicity.
So what about using both simultaneously in any chronic case - a Damp Heat clearing and a Blood moving formula? You could probably get away with that and not wind up in trouble. So it's not a bad option.
Thanks as always for your input, Erin!
Steve