Cat is vomiting, no apparent reason so far

I'm hoping someone here can give me some insight on my poor kitty's situation.  Background:

In the beginning of April (the 2nd), my younger girl, Keri, became ill, vomiting stomach bile.  I called the vet and got her in the next day.  She ran blood work and took x-rays.  No blockages or indications of infections, tumors, etc. and the tests all came back clean and showed good health. She was given an injection for dehydration and an appetite stimulant (as she hadn't eaten or drank anything in 24 hours) and we were prescribed Pepcid to be given twice a day for 7 days.  By the end of the 7 days, she seemed to be back to normal.

On the 25th, it all started up again.  We still had half a bottle of Pepcid, so I gave her a dose.  She vomited it back up immediately.  Called the vet and got an appointment for the next day and were told to keep trying the Pepcid until she was able to keep a dose down.  She was sick all day and through the night, nothing stayed in her stomach for more than a few seconds.  Vet took more blood and x-rays.  Again, the blood work came back clean.  The x-rays showed a what the vet said was a large gas bubble in her stomach and it looked like something was swollen and pressing into her stomach as well.  We scheduled an ultrasound for the 28th.

The ultrasound showed that the area around the pancreas was very inflamed and they also found what looked like crystals in her bladder.  The vet took a urine sample and more blood for testing, but assumed it was most likely pancreatitis and started treatment for that.  We were given more Pepcid, Buprenorphine for the pain and inflammation and an appetite stimulant.  We started the treatments as directed (Pepcid and pain killer twice a day for 7 days) and again, Keri improved quickly.  A few days later the vet called back.  All the additional testing came back perfectly clean and healthy again!  Even the urine analysis showed perfectly normal.  We were instructed to finish out the 7 days of medicines, since they were helping.

Which brings me to today, when Keri vomited stomach bile again this.    I gave her a dose of Pepcid and it has stayed down and seems to be working (no other incidents while I was at work).    So far, she is still eating and drinking.  If we have another incident, I'll call for another appointment.

Any thoughts on what else could be going on here?  My other cat, Anya, is perfectly fine.  Both girls are on the same food (was Blue Buffalo grain free previously, currently on Iams since Keri decided that the old food was the reason she got sick and refused to eat it again). 

Someone on the forum with knowledge of pancreatitis and vomiting should be online before too long. Good that she is eating and drinking.

Has she been on steroid?  Often pancreatitis stems from inflammation in the intestines.  The inflammation moves into the liver or the pancreas.  Sometimes it moves into both which is triditiis(sp).

There is a specific blood test for pancreatitis that can tell if it is acute or chronic.  There is a big difference between the two types.  The test is done at Texas A&M.  My IBD kitty had been misdiagnosed with pancreatitis until this blood test was done.  http://www.idexx.com//view/xhtml/en...menu/innovative-tests/spec-fpl.jsf?SSOTOKEN=0   tells a little about the specific blood test.  http://ibdkitties.net/   is also a good resource.  It includes info about pancreatitis 

She's never been on steroids.  She's 7 now, and up until last month, she's been the picture of perfect health, aside from her weight, my little piggy girl!!

The Spec fPL is the test the vet ran to check for pancreatitis, which she said came back negative.    Reading the IBD kitty site now.  Thanks for the link!

How often does she get fed? The vomiting of bile can be a sign of excess stomach acid, usually from going too long between meals. Does the vomiting happen at certain times of the day, like mornings?

It may be IBD, which often has this cyclical nature that you describe. Although difficult to diagnose, there is some indication in blood tests now through the cobalamin/folate test. Dr Becker has a good article discussing how to discern IBD from blood work: http://healthypets.mercola.com/site...012/09/24/pets-gi-inflammation-treatment.aspx   Since you've had bloodwork done, this may be something to discuss with your vet.

I was also just about to ask if the vet did a cobalamin and folate test from TAMU.

Well, if the spec fPL came back negative (which it did sound a lot like pancreatitis), then I guess there could be inflammation in that area still (also stomach, liver, duodenum, gallbladder). If the vet feels there is inflammation, the current regime (Pepcid, buprenorphine, and appetite stimulant), does not address this. You may also want to ask your vet about an anti-emetic such as Cerenia to help curb nausea and vomiting.

I know you said the vomit is stomach bile. Is it light, dark, foamy, watery?

Are they on a dry diet?

They were on a dry diet before Keri started getting sick.  They are on wet food now, as it seemed like it would be easier to digest.  They get fed half a can each (the small ones) twice a day, about 6am and 6pm. 

When Keri vomits, it's usually light yellowish and foamy.  Sometimes darker colored if she's eaten within a few hours.  This time around, it was just this morning that she got sick.  Last two times, it was a couple of times a day.

I don't think either of those tests were run.  Looking at the invoice from the last visit, the test run were:

CBC/Superchem/T4/UA

Urine Culture & MIC

Spec FPL - Idexx