What cat food is high in fiber for cat that gets constipated?



I have a cat that gets constipated often. He has been at the vet several times for it and has had enemas. I noticed that the canned food that he eats has lowered the fiber content. What canned food has a high fiber content that I can switch him to? I have 3 other cats so I prefer to first try a food that is not a prescription food.