After she dropped to 55lbs I took things into my own hands, I requested a TLI test be done, the vet pooh poohed it but 1 week later test came back positive.
We re-ran it again to be sure. Same results.

The female vet I worked for at the Emergency Vet clinic on weekends said get her
on enzyme powder immediately so I did, still didn't see much improvement so I looked at her diet.  Vets seem clue less about that. I tried every prescription diet I had access to. I tried every human grade high quality diet as well.  Lily seemed to do best on diet that contained less than 12% fat and less than 3% fibre.

After more searching I finally put Lily on BURNS Real Food for Dogs. It's got a lower protein than I'd like but I add cottage cheese.
Fat content is 7.5% and fibre is 2.5%.
Within just a few feedings I saw improvement in her stools, they will never be "quite normal" but they're pretty darn close and I'm happy with that.
Using this food had enabled me to cut Lily's enzyme powder down to 1/4 teaspoon per meal, one bottle of 16oz powder now lasts me about 8 months.

I supplement her diet with cottage cheese, a daily multi vitamin, B12, FOS
(frucctoogliosaccarides)  & an EFA capsule. Occasionally Dandelion supplement.
I tried MCT (medium chain tryglyceride) oil to no avail.

She gets metronidzaole (flagyl) for the occasional bout of SIBO which has only happened once this year. She gets low fat cookies for treats and very little else.
If I as much as give her a piece of chicken skin or anything else like that I can
count on a big blow-out the next day.
I do keep a very small bottle of the enzyme tablets on hand in case I do want to give her a treat of something else.  I tried prozyme but was wasting my money.

Lily now weighs in at about 75#.

Not a Vet or Vet Tech.....YET!!!
Ellen