Cat Vomiting since about May and continues

Question
even after several trips to the Vet.  He now n Hills ID for digestive problems, but that doesn't help.  I'm at my wits end trying to find out what is wrong with him.  After this last trip, they did find a urinary infections with a lot of blood.  But nothing for the continuing vomit spells.  It's not hair balls.  He eats and then will vomit, no set pattern for this vomiting.  Early evening, middle of the night, early morning, even before they are feed.  I'm almost at the point of taking him to another Vet?  

Answer
Hi!

I need more information to give you an idea of what can be wrong with your cat. How old is your cat? How many times does he vomit during the day? Did they make any blood work and what are the results? Is he neutered? What do you mean about urinary infection with a lot of blood? Does he have a lot of blood in his urine? Can he urinate, does he have problems urination, does he go to his litter many times during the day? Please answer these questions so that I can try to be of further help. Thanks!