If it's constipation, one thing you can try is "Cat Lube" treats by Veterinarian's Best. They're chicken flavored, and kind of big for a cat to eat all at once, so I just break one up over Smudge's kibble. He definitely likes it, and it hasn't got any of the petroleum that seemed to be irritating his urinary tract last fall.

If Gizzy's a canned-food eater, you can just get psyllium seed laxative for humans (unflavored) and just snip the end of the capsule, sprinkle it over his food, mash it in well (be sure it's mixed in, or it'll just collect in gelatinous blobs that he won't eat) and then mix a bit of extra water into the food.

Love, Columbine