I have a 16 mo. old son with CAH salt wasting. We have been unbelievably fortunate and he has not had diarrhea or vomitted yet. So I don't have personal experience with this but . . . both his ped endos have said to give him the solucortef injection if he vomits and is unable to keep his regular meds down. Then page them immediately to determine the next step. They both recommended me giving him the injection (rather than going first to the e.r.). I guess I have assumed that was to avoid a situation where we are waiting to be seen and trying to explain the urgency of his situation. They haven't focused so much on diarrhea, just said to make sure he stays hydrated, is able to keep his meds down, and doesn't show any signs of crisis (e.g. lethargy). Also, double his dose if the diarrhea is accompanied by a fever. We live in a big city so I think they tend to give me less instructions and more "page me" type advice. Hope that helps.