Also Known As: Donnagel, Palygorskite, Attapulgite
Palygorskite or attapulgite is a magnesium aluminium phyllosilicate with formula (Mg,Al)2Si4O10(OH)Â·4(H2O) which occurs in a type of clay soil common to the Southeastern United States. It is one of the types of fuller's earth.
Attapulgite is used widely in medicine. Taken by mouth, it physically binds to acids and toxic substances in the stomach and digestive tract. Also, as an anti-diarrheal, it was believed to work by adsorbing the bacteria or germ that may be causing the diarrhea. For this reason, it has been used in several anti-diarrheal medications, including Diar-Aid, Diarrest, Diasorb, Diatabs, Diatrol, Donnagel, Kaopek, K-Pek, Parepectolin, and Rheaban.  It has been used for decades to treat diarrhea.
Until 2003, Kaopectate marketed in the US also contained attapulgite. However, at that time, the U.S. Food and Drug Administration retroactively rejected medical studies showing its efficacy, calling them insufficient. Kaopectate's U.S. formula was changed to bismuth subsalicylate (pink bismuth). The next year (2004), an additional change in labelling was made; from then on, Kaopectate was no longer recommended for children under 12 years old. Nevertheless, Kaopectate with attapulgite is still available in Canada and elsewhere. Until the early 1990s, Kaopectate used the similar clay product kaolinite with pectin (hence the name).