You may want to try adding FortiFlora to the wet food as a probiotic. Some wet foods are mostly grain free...even Friskies just has rice so that's interesting you had constipation since alot of people talk about better bowel movements on wet food. Our cat with the urinary blockage had a terrible time with the Royal Canin dry prescription stuff, he LOVES dry food though and isn't good about portion control so wet is much easier for him. He gets the runs if he binges on dry food.