@granadilla so glad the blood test results came out normal. I am sure that is a big relief for you. While the UTI is annoying, it beats having pancreatitis and kidney issues.
If I recall from reading Dr. Pierson's site, I believe UTI is more common with feeding dry food. So now the challenge is finding a wet food for her sensitive tummy.
Can you force feed Marshmallow canned food if she won't eat it readily? That's what I did with Bonnie for awhile to jump start her back into recovery.
Have you discussed giving Methylcobalamin B12 shots with the vet? You can do the injections at home. IBD cats often have normal blood work (Bonnie always does) and methyl B12 is great for absorption of nutrients in an IBD cat especially when vomiting, vomiting and diarrhea are present.
It will be so good when Marshmallow is home again with you!