Mucoid plaque
Mucoid plaque or mucoid rope is a term coined by a naturopath and entrepreneur, purporting to describe a harmful coating of mucus-like material existing in the gastrointestinal tracts of most people. The existence of mucoid plaque has not been reported in the medical literature, and it has been variously described as "a complete fabrication without any anatomical basis", a "non-credible concept", and "a bold lie". An article from the Division of Complementary Medicine of the University of Exeter described mucoid plaque and other claims of "colonic autointoxication" as "a triumph of ignorance over science", based on "old bogus claims and the impressive power of vested interests."
Despite the absence of scientific evidence, mucoid plaque is discussed outside the medical community, especially within holistic health circles and in anecdotal accounts of colon hydrotherapy procedures. The idea of huge accumulations of fecal material in the bowel has acquired urban legend status.

# Background
The concept of mucoid plaque was coined by Richard Anderson,  a naturopath and seller of products which purport to remove mucoid plaque. Anderson claims that mucoid plaque is created when the body produces mucus to protect itself from potentially toxic substances. Anderson further claims that mucoid plaque acts as a health threat by reducing the absorption of nutrients, impairing digestion, providing a haven for parasitic microorganisms, behaving as a reservoir of toxins, promoting the development of cancer, causing skin conditions and allergies, and reducing bowel transit time. Anderson further claims that removing this allegedly protective layer is beneficial to health. These claims are not supported by scientific or medical research.

# Criticism
The major criticisms of the concept of mucoid plaque are that it has never been described in the scientific or medical literature and that medical doctors report that it has never been found in their patients. The existence of mucoid plaque is promoted primarily by people and organizations in the business of selling books and products aimed at remedying it.
Edward Uthman, a practicing pathologist and Adjunct Professor of Pathology at the University of Texas School of Medicine, has said on the basis of having examined several thousand intestinal biopsies: "This is a complete fabrication with no anatomic basis."
Another practicing pathologist, Ed Friedlander at Brown University, states, "As a pathologist, I have opened hundreds of colons and never seen anything like 'toxic bowel settlement'." Furthermore, in reference to purported photos of expelled mucoid plaque, he writes, "Sites they have shared include one depicting what I recognize to be a blood clot." It has also been proposed that the bentonite clay found in many popular cleansing products, combined with normal fecal matter during its passage through the intestines, accounts for the consistency of many of these alleged plaques.
A 2004 paper by Soergel, Tse and Slaughter on the relationship between lay and medical language uses "mucoid plaque" as an example of "non-credible concepts" used by healthcare consumers.
An editorial in the Journal of Clinical Gastroenterology described the concept of mucoid plaque and "colonic autointoxication" in general as characterized by "...false claims, a lack of evidence, big money, aggressive advertising,  disregard of risk."

# The John Wayne and Elvis Presley Myth
Advertisements for some products marketed to cleanse the colon of mucoid plaque claim that an autopsy of John Wayne revealed that the actor had over 40 pounds of plaque/fecal material accumulated in his colon.  In fact, an autopsy was never performed on John Wayne. Similar false claims are made about singer Elvis Presley.