sphynx diarrhea

When I got him over a month ago, everything was fine. I kept him on the same royal canin kitten dry food. Then out of nowhere 2 weeks ago he got the squirts. After a day, I got worried and took him to the vet, tests galore...all negative. I was told to give him a prescription liquid twice a day...

My sphynx is almost a year old. Caught her about a week 1/2 ago licking milk from my kids cereal bowls, and she had also licked maple syrup off my sons breakfast plate. Shortly after about a day later, she developed severe diarrhea. Its still going strong after taking her to the vet. They...