6 year old with abdominal pain?

My 6 year old has had abdominal pain (mainly around belly button on insides) for 3 weeks now. Took her to the dr last week and she put her on laxative bc she thought constipation. Well its been a week on laxative and she s going potty so much she cant go to school and the dr still thinks constipation is the cause of the stomach pain. She had an x-ray done today to check for constipation but I don t think its constipation. Has anyone experienced anything like this? She has no other symptoms just stomach pain daily.