I too had a diversion, with an end ileostomy in '17 (my history is very much like Lori's, I had fistulas, and abscesses). For a year after diversion, I endured the mucous drainage, which was so very unpredictable and intense and embarassing at times. My surgeon let me try Keflex (antibiotic), which seemed to work a bit, but not really enough to make it worth being on antibiotics long term. So, I put up with the drainage, knowing the plan was that my pouch was coming out a yr after the diversion, and everything would be closed up (Barbie butt). The surgeon really had no other suggestions/advice re. the mucous (for what it's worth, I was going to the Cleveland Clinic).
The pouch removal/BB surgery itself was a success - I was stitched on the inside of my butt, so recovery was a bit easier there. My stoma was revised due to (uknown to me) kinking. I had some complications (afib, low bp, an ileus), and had to return to the hospital for 10 days or so, but it was all worth it.
I wish there were more advice I could give you re. the mucous. Good luck with everything.