Hi, I've read similar posts about the topic, but I'm pretty sure mine is not due to vegetable fibres. I got diagnosed with IBS a few months ago as doctors couldn't figure out why I would experience nausea every once in a while (in the middle of the night). I've also been on a pretty strict vegan diet as I find dairy and meat products tend to turn my stomach.  Every once in a while when I have a bowel movement I notice these long brownish strings in my stool. They seem a bit too long to be fibers though as some of them are around 3" long. Could it possibly be worms or do produce fibers actually just look like that? I can also send you pictures of the strings through email if it would help identify these things. Thank you!