What causes pain inside the belly button area stomach of 7yr old?

Various: Many things can cause pain in that area. Usually pain coming from the large intestines will be felt in the belly button area. Illnesses can cause pain there. Constipation is a common cause, if there is no illness.

Many possibilities: You have to think about external as well as internal causes. Has there been any external trauma to the area in sports, playing, etc? Thinking of internal issues, is there a history of constipation, lactose intolerance, inflammatory bowel disease? Have the child seen by the doctor for a good history on the problem, and a thorough exam. Hope this is helpful.