I gave up Pentasa after my ears started ringing. That was a few months after I went GF. My guess is that I suddenly started absorbing too much of the salicylates.
I'm not taking any probiotics. I have a hard time believing they do anything except cost $. But I do eat yogurt a couple of times a week!
I haven't had any stool samples done. Like occult blood? Or looking for pathogens?
You are bang on!! I had to stop Pentasa, I now have a problem with aspirin. The salicylates in the drug then went on to cause me problems with salicylates in food. And, one of the worse symptoms is ear ringing!
Sorry you are back, but you are amongst friends!