Yes, this is related to CAH.  Those with CAH must be careful when sick.  If they are vomiting or have diarrhea they need to make sure fluids are staying in the body.  Usually through IV fluids.  WE always keep pedialyte pops in the freezer too.  Our endo believes that carriers can show some symptoms of CAH so I would assume that a carrier can dehydrate more easily than others.  I myself am a carrier and I do dehydrate easily.  I get panicky without water near at all times especially if I am active.  Julia