Possible parasites? Dried mucous strands?

I was diagnosed with IBS (and later Celiacs too) almost a year ago, but thinking it is something more than that. Basically, bloated all the time, nauseous, and total change in bowel movements for the last 10 months. I will go 2-3 days with no BMs, then a day of going every hour, but only soft, ribbon-like stools, and always with weird thread-like things in them - in every BM, no matter what I eat (even after eating gluten free for the last 5 months) - GI did one stool test for parasites, came back negative. There are tons of them in every stool, they never move , but I could swear they look "segmented" like a worm. They vary in length- from 1/2 inch to 2 inches or so - I was able to wash these two off and put them in a baggie. Any thoughts about this would be appreciated...I'm almost afraid to tell GI this - afraid he'll write me off as crazy...are there such things as private labs that I can send this to for analysis? Thank you! Tweet