Stomach Hurts While Bowel Movement In A Child. Vomited Little. What Is Wrong?

Hi; My five year old daughter just tonight has been complaining(screaming while on the toilet) that her stomach hurts. I asked where the pain was and she pointed to the middle of her stomach(around the belly button area). I had her sit on teh toilet for a good 10 mins or so, and about every 2 mins out of the 10, she would come off with this horrible heart wrenching scream. She did have a bowel movement , no blood , but loose. And she vomited very little(almost like a baby would spit up) She seems fine now, laying down in bed with trash can and all. She was shivering , but now she seems to be okay. Is there something more serious I should be concerned with? Thanks, Kelly