My cat has had red blood in his stool for several years now. We've run many tests at the vet and come up short on heartworm and the like. They tried to weed out food allergy by putting him on a corn free food (chicken soup for the cat lovers soul). He did get better for a while, but I think that may have just been the antibiotics that he was on at the time?... because the blood came back. Later, we tried another vet and another brand of food (taste of the wild -grain free) About 1 week after switching to this food, he got a sore on his bottom lip. He's having trouble eating and drinking. The vet gave him antibiotics and wants us to give benadryl three times per day. If that doesn't work, he has to take a steroid. She says these are also caused by allergies but wouldn't state if she thought it was the food switch. Right now, I don't know what food to put him on? Is this really the right treatment? Why do I feel like he gets worse when I take him to the vet?