Son has the runs how to get rid of them fast?

yesterday and the day before he ate 2 bags of small candys, the bags where probably the size of 1 1/2 small toothpaste bottles on top of each other plus today we baked cookies so we had some of those. Is that the cause of the diarrhea? if it is, how can we stop it? he took a chewable imodium and hes still running back and fourth. any non medical solutions?