I've had IBS with Diarrhea for about 2 years now, and after many trips to the doctor and many medicines tried, I found that the best way to control the cramping and diarrhea was taking 2 Immodium AD and 1 Levsin every day (and possibly at night if needed). I used to miss school very frequently because of IBS and after I started taking these medicines I stopped having diarrhea and stomach aches all the time. I've been taking these for about a year now and I've rarely had any IBS problems anymore. Now I can finally eat whatever and not have to worry that the next day I'll feel like ####, or stress out over the weekend about missing school. I'm not saying it works for everyone, but I would definately give it a try! Also, if you're like me and worry about the medicine not kicking in soon enough before school or work, I suggest setting your alarm an hour early and take the medicine real quick and hop back in bed and let the medicine kick in.