The National Institute of Diabetes and Digestive and Kidney Diseases recommends that children with any of these symptoms or issues should see a doctor for diarrhea:   -Dehydration -A fever of 102 degrees or more -Stools that seem tarry or black in color, or stools with blood or pus in them -Diarrhea that's lasted over 24 hours   You should go see an urgent care doctor or urgent care pediatrician. One of these professionals should be able to see your child right away without the need for an appointment, so your child won't have to wait to see a doctor.