URGENT! My cat has fecal incontinence and diarrhea–I’m really scared and the vet has been no help!?

So I have spent $1100 over the past month trying to figure out what is going on with my cat and so far, it seems like she gets worse every time I take her to the vet. BTW, in case any Los Angeles people are reading: I took her to Dr. Kent from the Westside Hospital for Cats (who is apparently rated very highly on Citysearch), but it seems like my cat is getting worse. I’d take her back AGAIN, but I’m a grad student and I can’t afford it. I’m hoping that her symptoms will pass, but I also know that diarrhea can be deadly for cats.***This is what’s happening:***She has had diarrhea since Sunday 12/6 (took her to the vet 12/8, will detail below). But tonight, just a couple hours ago, a new symptom seems to have developed: poop is now just oozing out of her rectum. I have found two smallish lumps in two places she has sat in for prolonged periods of time, and multiple places where “pieces” seem to have fallen. And I’ve checked her butt, and little pieces of poo are indeed oozing out. But her rectum does not appear “open” nor does it seem to be sticking out (prolapsed?). She’s also acting completely normal.***My cat’s background (I’m not sure if vets or vet techs will read this, so I’m just going to write everything in hopes someone will have an idea, so please feel free to skim):*** – Her name is Zhoul (we named her after a line from Ghostbusters: there is no kitty, only Zuul). So that should give you some idea as to her temperament. She’s really nice to me and my husband because we’ve earned her trust, but she hates new people.– She was a rescue cat and was born in 2001. She’s currently 8.5 years old. We’ve had her for 8 years. And she seemed very healthy until recently.– She’s a medium hair (maybe short hair–I never knew there was such a thing as medium hair until recently) calico cat.– We adopted another rescue cat in August, a male, he’s 2 years old, and we introduced them slowly, but Zhoul wasn’t getting along with him for about 3 months. No cat fights but constant hissing and batting. Xander is very good natured and doesn’t hiss or bat her back, though.– In November, we took her to the vet for her aggression towards Xander and excessive licking (she was picking patches of hair off her legs–more than normal, because she did that even before we adopted Xander. In March, when we took her for her annual checkup Dr. Kent said it wasn’t a problem). – At this appointment on 11/11/09, the vet prescribed Clomicalm/Clomipramine for both the aggression and licking. The vet techs at the doctor told us two different things: give her a whole (5mg) tablet every day and give her half of one. I asked a third person and they said give her a whole one. On 12/8/09, we found out what we were told was wrong. So, since 12/8, we’ve been giving her half a tablet (which is so much better, when she had a whole tablet, she was stoned all the time, but on half a tablet she seems more like her old self).– A blood test was taken on 11/11 that came back clean.– 2 fecal tests have been taken (11/11 and on 12/8) that have come back clean.– She’s allergic to flea saliva, so she’s been on Advantage since November (vet said that may have been contributing to her aggression).– She’s been on Prenisolone (5mg–I was told it’s a steroid) twice in the last month. 11/11: to help with itching from flea allergy until Advantage kicked in. And on 12/8 they put her back on it for her bowels, see below.– Vet techs told us that the vet told them that her diarrhea could be early onset Irritable Bowel Disorder and that the Prenisolone would help with that (the vet did not see us on Tuesday, but relayed all of the information through vet techs for reasons that are maddening, but seem kind of unnecessary at this point in the story, so I’ll spare you the details unless you really need to know).***What The Vet Did Tuesday:***So I took her to the vet on Tuesday 12/8 for the diarrhea problem and they took the second fecal (the results came back clean again on Wednesday). On 12/8, they gave her antibiotic shot that’s supposed to stay in her system for 2 weeks. They also gave her a steroid shot. Then they gave us another bottle of Prenisolone and she’s supposed to have one every day for 5 days and then one every other day until the bottle is empty. ***What happened right before the fecal incontinence (aka before the diarrhea started leaking from her butt):***Tonight she was scheduled for her second dose of Advantage, so we gave her that. We also gave her half a tablet of her Clomicalm and her full tablet of the Prenisolone. About a half hour later or so, we noticed the first soft lump of poop on the floor where she had been sitting. **What I’m looking for:***Any useful advice (or websites) would be appreciated, aside from the obvious: find a new vet (I’m already on it, all of my cat’s future visits will be at another vet recommended by a friend, but I can’t afford to take her again t