Kelcee's vet visit today

She used to eat a lot and was 13 pounds, now 7. Used to when she was younger, she ate Iams, then I changed her to Wellness when she had blood work done and the kidneys didn't look perfect, then the #'s improved. A different vet, same place, said to put her on low ph food and I mixed it, the Waltham and Wellness for a couple years. Then the #'s moved up a tiny bit and she said to do just Waltham. And she has been on it for about a yr. With each change of food she ate less, but also getting older.The vet also thought it might be hyperthyroid. He originally said 4 things could be wrong the others were cancer or linfoma and kidney. So I guess with her symtoms he thought that IBD might be the one she had. H-thyroid they eat more and pee more, and she doesn't. so I don't really know what to think. 'As I said before, her thyroid # was 2.3, the high side, for old cats 2.5 is the highest.
The vet called this morn, (Dr. Curt) to check on her. Since she ate 'some' of the Hills he said let her go one more day and call him first thing in the morn. She hasn't pooped since Saturday, and I told him that, but she hasn't eaten enough to make her. I'm getting more scared now.
I got the ingredients of Wellness Salmon, and it does have chicken liver, but I may fax it to Dr. Curt and see if I can try that too.
This does have me upset, I look at that cat bowl 1000 times a day to see if any is missing.
Poor Kelcee, she has to take pills and that freaks her out too. And me too. And no ice cream at night and no treats when the pups are getting theirs, everything is changed and she hates it.