Looks very parasitic. Very similar to what Morgellons sufferers such as myself and scabdrggr have posted photos of. Scab makes references to huge quantities of this stuff in some Morgies, and swears fenben is the solution. I don't disagree.
When I was really sick, I used to torture myself trying to match the stool matter that came out with foods I had eaten. Then I ate anthelmintics every day for 4 months and 3 days a month for another 2 years. Now my stool is 100% brown and consistent. I think since I've been a child that "undigested food" in my stool is quite rare. 99% of the strange stool stuff was the product of parasites/ Morgellons.