My 18 month old has had diarrhea for 24 hours do I take her to the dr?

See below. As long as your child is not showing any signs of dehydration, there is no need to go to the doctor. If the inside of her mouth looks dry, her hands and feet are cold, or she is not making tears when she cries, she needs to be seen. Replce the fluids she is losing with pedialyte, if she will take it. Feed her a regular diet with extra noodles and yogurt.
Not really, not yet. If she is not having fever, appearing sick, and she is eating fine, i would just monitor her for now. Children do get sick--colds, diarrhea, vomitting, ear infections etc... All the time and most will resolve with just supportive measures. If she gets worse over next couple of days, then take her to the doc. Good luck.