Not that this helps much, but I know EXACTLY what you feel like. At this moment Jasper is suffering with diarrhea. He is pooping on the bed, it's pudding consistancy, no meds have helped him so far, we've done tests......and this is exactly what happened with Lucas before he was found to have cancer and had to be PTS. I am certain more tests will follow.

But, I have one distinct difference....my vet isn't a fan of unnecessary tests. She is known to attempt a medication that could help before knowing the specific cause. Her idea is....."If the medication works = GREAT, if not, we know it is not that particular problem". Then we move on to another idea.

There is no magic potion to handling the stress. I WILL be hard. And when episodes come close together, it is even harder. So just focus on the cat's well being. Take into consideration the cat's age, prognosis for a good quality of life, and YES, your monetary situation. You will know the right thing to do if you have faith in your feelings.