Simple description: Purple, "500" imprint, round / disc-shaped almost exactly the same size as a Spree -- bigger than an M&M, smaller (diameter) than a dime. Color, imprint, and size are unmistakable but I can provide a pic if there's a way to do so here...

My gut feeling is that this is an Immodium generic, but I can't verify this anywhere.

Thx!