Hulda Clark has a picture in her books that looks just like this, and she says it's Fasciolopsis buski.
But then this website shows pictures that look just like this.
According to this site it's Borrelia burgdorferi, the cause of Lyme disease. http://lymephotos.com/bb/index.html
To this day I am still not sure. I've gotten these in my stool many times.