I carried Immodium AD around for years. The liquid worked fast so that is what I had. At the first cramp, I would take that.
Years ago, I was on Lomotal. But then a Dr. told me the immonium AD worked just as well. Keep it on hand when you eat out. Taking it before eating helps too.
Many a time I had to also make a dash to the bathroom for a good while until it was all over.