Hi Corinne
You're absolutely correct in your assessment of BZYQT. That it can also deal with the opposite situation - diarrhea - tells us that it is a Harmonizing formula, which was a term only used in Chinese medical works for a formula that deals with opposites.
From a physiological perspective, it addresses the Liver Qi stagnation and Blood deficiency that creates constipation; yet it raises the Spleen Qi to address diarrhea.
My approach to medications is to go beyond what they are accomplishing by introducing a herbal formula, and only once that has been achieved, begin reducing drug doses. That way, I can avoid ripping the rug out from under a patient by removing the drugs, if my herbs meanwhile turn out to be not effective.
Regarding lymphocytic-plasmacytic inflammation, the assumption that most veterinarians make is that they must be dealing with an immune mediated condition. Note however, that lymphocytes and plasmacytes predominate in any inflammatory process that fails to actively resolve. It is the cell population correlated with subacute inflammation. For subacute inflammation to progress through the process of 'active resolution', certain cyokines need to be elaborated. All acute acting anti-inflammatories suppress the production of those cytokines, stopping active resolution from occurring. The patient stays in a perpetual state of subacute inflammation as a result.
The cytokines and steps involved in active resolution have been known for decades but despite all that research, no drugs have been successfully developed to push the process forward. It has been discovered, however, that the promotion of active resolution is a big reason why alternative therapies work so well, explaining their popularity. They are filling a pharmaceutical void. Cardiovascular disease is the top disease of concern relating to the failure of active resolution, so it dominates the articles published. Note, however, that the inflammatory processes involve affect all tissues
Hopefully this clarifies things for you
Steve