Sadly IC does not discriminate because of age and is a very painful condition. The cause of IC is not really known and can be different even between individual patients as well. Simple can often vary from feeling really good to hitting a flare but
Actually more and more doctors are recognizing IC in children and honestly it is harder to get a diagnosis then for an adult because doctors did not know to look for it in children. I am an IC patient and support group leader, I personally think I have had IC since childhood but it was only diagnosed much later as an adult. By then I had suffered many years!
Your daughters symptoms do sound very much like IC, I am afraid. If you want to pm I will send you information on where to get info. and help.
2years ago as I was building the medical support base for our support group, I was surprised that the pediatrician had never even heard of it, in truth many doctors had not. At her request I did a lot of research on children with IC, and was sadly disappointed by the limited info. specifically for children. I have since written a book for children, that I am simply waiting for my illustrator to finish her part. Since she is in college doing her internship as a PT, it is taking a long time...,
Your daughter however is older and can most likely still learn from the many resources available for adults etc. Though there are no cures for IC, there are many helpful coping tools. I was considered one of my doctor's worse yet, now with treatment I am soo much better and even SOME days have NO pain!
Anyway I would be glad to help you anyway that I can! I also know as a mom myself, that it is easier to go through things yourself that to watch you child go through them!
I want to commend you for believing your doctor and obviously from the list of things she has been through, your posting here etc., it is clear that you have not given up but are fighting for her to get her some help! This is the greatest asset she has, because in all patients, esp. in children some doctors and even parents, will tell them the pain is their head etc. It is not by the way. IC can be a very painful debilitating disease.