The doc told me I had IBS about 3 years ago. It was all very sudden during a period of stress, leaving me suffering from agony in my tummy and *ahem* the runs a lot.
Fibre sachets sorted me out and imodium when I needed it. I know stress is the main cause of it so avoid it as much as possible (easier said than done!). I haven't really been able so far to pinpoint which foods trigger it, apart from junk food like McDonalds.
Another thing I find is that if I rush my food and eat it really really fast it will give me a bad tum too, and I will be on the loo 5 minutes later.
Anything that tummy disagrees with will give me a churning, vibrating, rumbling type sensation, which I always think feels like a washing machine going through its cycle.
This week I have only had 1 bad 'episode' when I ate extremely quickly so it was my fault. It seems that atkins suits my IBS. I haven't had washing-machine stomach at all (but I have had windypops once or twice).
My tips - eat slowly and 'be prepared'!