I'm sorry, but I have to go with the oil theory. I'm new to this forum, so I may be about to say a taboo word: colonic. I've had some. On my first one, about 5 minutes into it, a gush of green was dispelled. The woman conducting it was very happy, saying that was bile. As nothing else during the session looked anything like that, and I hadn't had lime Kool-Aid (ha) I think that's what it was. Where I go uses a "viewing" area about the size of a fish tank and about 10 feet long. It's amazing to see what you ate 2 weeks ago floating down. I literally saw a mushroom from 3 weeks prior. No kidding.