My message to anyone reading this is to be persistent. If you feel there is something wrong, push your doctor to do something about it.
In Jan 2013 I visited my GP as I was experiencing stomach pains. The doctor decided it was probably related to certain foods in my diet so didn't carry out any investigations.
At the time I felt I wasn't being taken seriously because I was so young.
In February the pains became severe so I called an out of hours GP who suggested stomach ease medication and to see my GP for further investigation. The pain passed again that same evening.