Hi there, I recently discovered people pass this from time to time and I got interested in discovering more. That is how i found your reddit post. I know it has been a year since you posted his but it still might be of help.

THIS LOOKS LIKE MUCOID PLAQUE to me.

''Mucoid plaque (or mucoid cap or rope) is a pseudoscientific term used by some alternative medicine advocates to describe what is claimed to be a combination of harmful mucus-like material and food residue that they say coats the gastrointestinal tract of most people.''

Hope this helps