My son is 15 years old and has had diarrhea 16 days. He s been to the pediatrician and she s ordered a stool sample but I m worried about dehydration . We Sony know what s wrong and he s experiencing symptoms such as, waking up with arm from elbows to tips of fingers numb (fail asleep), fatigue, dry mouth, sweating while sleeping, loss of appetite, mucus in diarrhea and possibly more symptoms he s unaware of as being important. He s not running fever, no blood in stool . At what point do I start to worry an bring him to the ER?