First, you should try to determine what is causing your cat’s constipation. Make sure his litter box is clean and his water is fresh. If there has been a change, such as a new addition to the family or a move, try to ease the transition by spending more time with your cat and working to get things back to normal quickly.
If your cat has constipation due to hairballs, you will probably notice hair in his stool or that he is throwing up hairballs. You can treat with hairball remedy from your local pet store.
Diet changes can help a cat with frequent constipation. Special high-fiber food blends, mild laxatives and rice bran or powdered psyllium supplements can help too.
If you have tried increasing the fiber in his diet, and all other factors have been considered, take your cat to the vet to have him checked for renal disease or other problems that can contribute to constipation. In some cases, your cat may appear to have constipation and visually strain with bowel movements, but have another condition, such as colitis or a urinary tract infection. If you feel your cat is suffering from more than constipation, schedule an appointment with your vet. It is better to err on the side of caution.
Most cases of constipation in cats can be easily remedied with diet changes and attentive care.