My chihuahua was spayed Monday, now having diarrhea.

My 5 year old chihuahua was spayed on Monday. I keep calling the vet for all these other little things going on but they keep telling me she’s fine. Two days after surgery we went in and got some xrays, they said she was perfectly healthy and recovering smoothly. The only issue was it looked like she hadn’t pooped in days even though she’s been passing normal stools since the surgery. We went back in for another check up yesterday since she was freaking me out with all the trembling she was doing. I think she may have also had a fever, her belly and tongue were very hot for some reason but she was still acting pretty normal. Again, they said she was fine and if she wasn’t showing any symptoms in front of them they couldn’t detect any other issues
Ever since she got spayed she hasn’t been too active. She doesn’t really have an appetite in the mornings. She’s been sleeping a lot. Her poops have gotten softer with each passing day, but today it was very runny and a greenish yellowish color. Could this be from her medicine? She takes half a Rimadyl every 24 hours and 1/2ml of Gabapentin Liquid every 12 hours. I have been giving her a few extra treats and give her the rimadyl wrapped in a little bit of cheese.