Older cat with bowel problems... please help!

[pittsburghcats]

Hello,

I have a 12 year old cat who is unable to have a bowel movement without the use of laxatives. I have taken her to the vet and he doesn't know the underlying cause, just that her rectum is not working as well as it should. The problem is, she keeps getting filled up with poo, and every time she does we need to take her to the vet to get cleaned out (which is not cheap). So far she has gotten cleaned out twice in the past 5 months. I've gotten her to the point where she has a bowel movement every 3 days or so, but she is still filling up. Currently she is receiving prescription laxative twice a day as well as mineral oil in her food. I can't keep shelling out money to get her cleaned out every couple of months... but I cannot bear to think of putting down an otherwise healthy and happy cat purely for money reasons. This is causing an immense amount of stress between my boyfriend and I for we love this cat very much and don't want to put her down. Does anyone have any other home remedies for cat laxatives? Any help is greatly appreciated!