Thank you all so very much for your suggestions. . I spoke with my vet (like you suggested)and explained the whole situation with him and he suggested that since massaging Katies' rectum with the vaseline works, cause she licks it, that i should try putting vaseline twice a week on her and see how this works.
Cause he just saw her about a month and a half ago and she got a very good clean bill of health. If her constipation should happen again in about 2 or 3 months time, after applying the vaseline every two weeks, then i will bring her in to have her checked out. Also 4 feline house, no need to worry, it is definitly not a bladder problem.
Thanks again everyone for your input on this as i have made a note of all your suggestions for future references, if i should need it.
Meow meow from Katie, who thanks you too.