Dear of troy: I have downed many a big swig of Kaopectate years ago, and never thought of what the "pect" meant. I suspect it is mostly to make an acceptable stable liquid.
Particularly in the South liquid preparations sell much better than tablets. Sometimes leading to tragedy. When sulfanilamide first became available, a large pharmaceutical company had a chemist find something to make a liquid preparation. He discovered that sulfanilamide dissolved readily in diethylglycol. They put it on the market, and numerous deaths resulted.In theri haste to get it on the market, nobody had thought to question safety of diethylglycol, former principal ingredient in auto antifreeZe!Here's URL aboutg it:
http://www.iqa.org/publication/c4-1-41.shtml