I seriously doubt that the tissue was stomach lining. The protective lining of the stomach is very thin and not something that just rolls down the digestive tract! BUT it could have been chaffe. Since I've been taking Julia's stuff - CB and GCG, the chaffe has changed appearance. It's really very strange. Where before after a flush I'd see some chaffe, but it was loose, duffuse and not much. now I'm seeing a lot, and it looks very weird. Kind of like the algea in a sewage runoff. It sticks togother like a lining. Maybe that's what you saw?
How lucky for you that you can visit Julia's store! :) I'd love to have a resource like her nearby. :)
Try a dose of heating pad and massage to your abdominal area - sometimes after doing all that work, the intestines get a bit twisty and so spasm. A colonics tech told me she sees that happen a lot. :)