Denise described the test.
First of all pancreatis can only be diagnosed by something called a PLI test. I very much doubt your vet did that as results have to be sent away for to texas and it takes a few days to get them back. Ask your vet if he did that test and if not, get one done.
If your cat does have it, the main thing is diet. I know the vet will want to prescribe prednisone which can cause other problems but if you work and get the diet right then it may not be needed. Dry foods are NOT good for any cats and especially for this disease and you do not want to feed the crap the vet sells.
Many cats do well on a quality low fat diet. You want to keep the fat content under 35%-40% of calories or 4% fat if you use the labels instead of the link for a food chart I will give you. The problem with lowering fat is that usually raises the carb levels in the food. To combat this you can add some chicken breast to the diet which will lower the fat content. You want high quality food like merrick if possible Also, I would get some acidoupholous from a health food store and sprinkle a bit over the food.
If you really want to do what is best then a raw food diet that you make is best for a pancreatis cat. I do not do this but many people I know do that have cats with pancreatis and have had alot of success. There is work and an initial investment as you would have to buy a grinder. If interested in this, I will send you a link on how to prepare it
If you get this diagnosed properly and you are sure about it, you will want to learn about pancreatic enzymes, get b-12 shots and also learn how to do sub-q fluids which can be done at home. Also keep some pepcid ac in the house for flareups and upset stomachs. 1/4 tab of it 2x a day (ASK YOUR VET AS I AM NOT ALLOWED TO RECOMMEND MEDS HERE) or the vet can sell you injectable pepcid,
Don't mean to scare you with all of this. Realize that with the proper diet, it is possible to never see pancreatic fllareups again
Link to the food chartshttp://www.geocities.com/jmpeerson/canfood.html