My 5yr old has stomach pain around her belly button with diarrhea. a rash always follows the next day. i have taken her to her doctor but no answers.

Celiac disease?: If this is a recurrent condition, diarrhea followed by an itchy rash, I suggest your child be tested for Celiac disease, (autoimmune, gluten sensitivity) often underdiagnosed because the symptoms are very non specific. (Glutens are a form of protein found in some grains). Of course, she could also have any of the more common entero-viruses that usually cause diarrhea associated with a rash.