Hi. My Daughter Is 15 Years Old And Very Healthy.

Hi. My daughter is 15 years old and very healthy. She is a year round swimmer. Two days ago, she developed a "side stitch" on her right side behind her rib cage. She says it hurts all of the time. I thought she may be dehydrated we increased her water intake and had her drink an electrolyte beverage today. It's not better. She doesn't have a fever and has not been nauseous but says she doesn't feel "well".

Do I need to get her in to the doctor or should I wait to see if it dissipates?