I have a 14 year old female cat. I had her spayed as a kitten. She has been in good health with yearly vet check ups and is up to date with all her shots. She has a problem recently with being bound up. The vets office prescribed special food and said mix pumpkin with her food. This works somewhat but she does not care for the pumpkin. The vet also said to mix metamucil with her food. I also give her milk, when she decides to drink it. Is there anything I can give her to keep her from getting bound up?