Slouchy, you could also see about getting a prescription for Immodium (Kirkland Brand) through your doctor and compare the costs between the Lomotil and the Immodium. When Costco started limiting how much you could get, the clerk at the pharmacy suggested getting the prescription. You may find it less expensive doing it that way.
Cash at my dose was around 170 per month from the Pharmacy but it was well over a year ago when I checked so I could be fuzzy. Still, compare that to 10 dollars per month cash OTC with 7 dollar 400 pill packs of yesteryear.