Our first set back

We were at 8 days post op and things were going well. Then we hit a bump in the road. Casey had diarrhea late night on day 8 and then the next morning on day 9 he vomited and continued with the diarrhea. I was not sure what to think at first. Casey has had a history of an unsettled tummy and been known to vomit here and there. We decided to keep an eye on him. When day 10 came and the vomiting and diarrhea did not let up and that no food was getting in or what did get in would not stay in, we decided to call our regular vet. they suggested we come in for a look. we brought a stool sample and now his runny stool had red blood in it. I was in tears. So worried and scared. Normally I would not be so worked up, but he was only a week and a half out of a major surgery and he seemed so fragile oppose to the days prior. Lethargy was setting in too and he was miserable. I couldn't continue to see him like this. My husband and I loaded up the kids and Casey to visit the vet. Our vet we typically see was not on as it was a Saturday. We saw another vet whom we had never met and did not know Casey. What can you do? The vet we normally see is also the owner of this vet clinic where Casey has been a patient since he was 8 weeks old. We really trust this vet and he has been helpful over the last 6 years with any issues that arose.
So this vet sees Casey and I am so cautious. The floor is linoleum and I don't feel as though she is being cautious enough around the TPLO leg! She taps his hind like you do to an animal after you pet them, but not on the surgical leg...come on! She decides to take blood after a physical exam. She decides to take blood where Casey is shaved from his IV from surgery. Not a good thing to try to take blood from veins that were used! She should have know this before trying 3 times and sticking the poor guy! He has been through enough. As she is taking the blood she lifts the front paw! I am having a heart attack and saying please let him lay down. You can not take a leg from him to take blood when he only has two other good ones to balance on! Am I being an over protective Mom? She she says to sling him with my arm. I did so, but was pissed the whole time. Truth is Casey is 100lbs and if he was to fall and I am squatting to hold him, we were both to go down. The whole visit didn't sit well with me. The vet seemed to think it was a result of his nsaid Duramaxx. He was no longer able to tolerate it. I guess they are quite harsh on the intestines and tummy. She ran the blood work and stool sample and said she would call with the results. We were sent home.
Hours later my husband calls as we had not heard and she had not run the test yet. She calls a half hour later and says that all came back negative for any infections and that his liver came back good too. That was important to hear as the liver can have damage from these powerful nsaids. I was so relieved to not have an infection! So they just said to keep with the bland diet of boiled chicken and rice.