This affliction, which may affect up to 10 percent of schoolchildren and is 10 times more common in boys than in girls, appears to be caused by a poorly understood malfunction of the central nervous system. For practical purposes, the term also includes parts of other organs, such as the colon, which adjoin the ovaries. Your daughter apparently has fluid-filled cysts that lie in or around an ovary. Usually, these cysts are benign, but they can cause pain. If so, they can be surgically removed.
Ultrasound tests are safe and inexpensive methods of monitoring the size of adnexal cysts.