Hi Sam,
For future reference, I'm able to tell when you've posted a reply to (i.e. updated) your previous post.
If the BZYQT has been in use for a substantial period without incident, then it's recent changes that might have provoked the loose stool. The raw diet or the foreign body are the most likely possibilities. If this is accurate, then maybe the first thing we should do is move back to a home-cooked diet. Still try to stay away from processed.
Once you've ascertained the results of the diet, then you're ready to make herbal changes. I'd make them one at a time, too, unless Timber still does terribly. Then simply try the SRT and stop the BZYQT. But if he stabilizes again on the BZYQT and home-cooked diet, then we probably want to start by just adding SRT into the mix. If he does even better, then we can wean off the BZYQT.
That's how I'd handle things if Timber was my dog. If he's still struggling, bring him to the course in Seattle and I can try to have a look during the break.
Good luck,
Steve