I too had troubles remaining continent after my IBS flared up terribly. I was started on Symax-SR, and since then have had very few incontinent episodes. My gastroenterologist told me that the incontinence is due to spasms, which is why we can't "hold it." Because IBS is affected by stress, strong emotion, etc, that is why it happens when you worry. Talk to your gastroenterologist, & good luck!
Meggy, I have been struggling with the same 'celiac vs IBS' question for over ten years now. In my case the blood test was negative but the biopsy questionable. So they treat you for IBS and send you on your way. It does seem like stress makes symptoms flare up, but that would be true for most "organic" diseases as well as IBS.
It is possible that one biopsy could miss the celiac - for instance if you'd been going light on gluten in your diet, or perhaps they biopsied an unaffected area. And there are other conditions that can mimic celiac disease, such as lactose intolerance or food allergies.
The best solution I've found is to just experiment with your diet until you find what works best, and do what you can to minimize the stress in your life. That may mean making some sacrifices, but you'll feel a hell of a lot better.
Good luck to you, and don't stop pursuing the celiac question if your 'gut' tells you there's still something wrong.
Email me if you like - I would very much like to see how similar your experience is to mine, as far as symptoms, etc. ***@****