If you ask Colonix and Oxypowder they won't say there is because thereis no official medical term.

People here on the forums say they have seen it. But you never hear that they have lost 20 lbs or so.
I have used Oxypowder that is a 7 day cleanse and like it, but you don't see anything because everything gets liquefied. People that see things have often used fiber and bentonite.

Here is a link with pictures from someone who wondered what it was. This answer is from Andreas Moritz but most feel that MP exists. So keep reading and make up your own mind. Don't forget that supplements is also a business.
//www.curezone.org/forums/m.asp?f=337&i=11523
//www.curezone.org/forums/m.asp?f=337&i=11545

On day 3 of P+B shakes I expelled quite a bit. By day 4, I was completely cleaned out. I didnt use anything else but the parasite tincture with it. No parasites! :( but at least I did release mucoid plaque.

I've done a Colon Cleanse and the rubbery mucoid plaque that comes out is actually nothing more than the psyllium husk that is ingested. Psyllium husk absorbs water and forms a gel and forms a rubbery consistency as some of the water is removed. I noticed this even before doing my Colon Cleanse while using GNC Colon Pure, which is nothing but pure phyllium husk. A clear gel formed at the bottom of my blender when I mixed Colon Pure with fruit juice and was difficult to remove the following day. The phenomenon of rubbery excrement being produced will continue on and on for as long as a person ingests large amounts of psyllium husk. It is wrong to portray this execrated substance as being some sort of mucoidal plaque that has resided in the intestinal tract for years. It is not, and one needs to ask a doctor, preferably a gastrointestinal surgeon, if there is any such substance as mucoid plaque and if so, just what can be done about it.